Basic Trigonometry: Sin Cos Tan (NancyPi)

Published on May 15, 2018 by

MIT grad shows how to find sin, cos, and tan using SohCahToa as well as the csc, sec, and cot trig functions. To skip ahead: 1) For how to find the adjacent, opposite, and hypotenuse sides of the right triangle, skip to 1:13. 2) For how to find the value of SIN of theta using SOH CAH TOA, skip to 3:16. 3) For how to find COS, skip to 4:15. 4) For how to find TAN, skip to 4:56. 5) For how to find CSC, SEC, AND COT from the sin, cos, and tan functions, skip to 5:56. 6) For harder examples of how to label the adj, opp, and hyp sides if the TRIANGLE IS ROTATED on its side or upside down, skip to 8:32. Nancy formerly of MathBFF explains trigonometry basics.

For MORE TRIG: how to convert between radians and degrees, jump to:

Follow me on Instagram!
Follow me on Twitter:

SIN COS TAN: If you have a right triangle with side lengths given and an angle (theta), you can easily find the sine, cosine, and tangent trigonometric functions. Remember that the longest side of the triangle is the 'HYPOTENUSE', the side directly opposite theta is the 'OPPOSITE', and the other side next to theta is the 'ADJACENT' side.

Once you've identified the hypotenuse (H), adjacent (A), and opposite sides (O), you can find Sin, Cos, and Tan using these trigonometric ratios:

Sin of theta = Opposite over Hypotenuse (SOH)
Cos of theta = Adjacent over Hypotenuse (CAH)
Tan of theta = Opposite over Adjacent (TOA)

The mnemonic SOH CAH TOA can help you remember which sides to use for the sine, cosine, and tangent trig ratios. For instance, SOH stands for Sin = Opposite over Hypotenuse

CSC SEC COT: If you need to find one of the other three trig functions (cosecant, secant, or cotangent), the easiest way to find them is to first find Sin, Cos, or Tan and then take the reciprocal (or flip) the fraction, since:

Csc = 1 / Sin
Sec = 1 / Cos
Cot = 1 / Tan

For example, if you find that Cos of an angle is equal to 3/5, the Sec of that angle would be equal to 5/3.

For more of my mathematics videos, check out:

Category Tag


Advertise here. Telegram, Signal - Call/message +1-868-308-4028.


  • Oscar WF 4 years ago

    Thanks Nancy! <3

  • How To Vegan 4 years ago


    • Walt R. Buck 4 years ago

      Her hottt what? I bet you’re talking about her markers aren’t you?

    • Monel Funkawitz 4 years ago

      Looks like Olive Oyl.

    • Owari Chan 3 years ago

      of all places you can go to make this comment you make it on a math video

    • Baljeet 3 years ago

      @Owari Chan lol all the comments are like: thanks for the help! and then there is this guy…

    • jordyn lilyann 3 years ago


  • Nomon Munir 4 years ago

    that SohCahToa stuff….man those were the good days

    • Sid 3 years ago

      What u talkin about, we struggling here

    • Vintage Prince 3 years ago

      @Sid real talk

    • Ben Animate IT 2 years ago

      @Sid real talk (2)

    • Gaming Channel 2 years ago

      What I have understand from those sight is that if you see a number, for example 4/3 you are going to switch them to opposite side which can be 3/4

  • Flashman9090 4 years ago

    This video would have been really helpful 3 months ago. Thanks for this anyway it was still very helpful.

    • Henry Wang 4 years ago

      Geometry class? Same case for me

    • Flashman9090 4 years ago


    • Jillian Tauro 3 years ago

      Hi there flash fan

  • In_Motion96 4 years ago

    Nancy is on a roll 😍
    I’m going into Calculus I in a few weeks
    Pray for me 🙏🏻

    • UnderBridge Rock 3 years ago

      Just stay calm, that’s the secret to Math. Nancy’s cool, calm and collected like most mathematicians, go be likewise.

    • Ken Kaneki 2 years ago


    • Ross 2 years ago

      Calc seems harder than it actually is

    • Someone 2 years ago

      @UnderBridge Rock Well I mean, it’s not like they can do anything other than be cool, calm and collected? It’s not as if they’re screaming in their minds and panicking about the numbers lmao. It’s just an understanding! Understand it and you’ll be fine lol. Faking the “cool, calm and collected”ness won’t do anythinggg. I find it kinda funny that you said “like most matthematicians”, implying that some are freaking out while they understand it? xD. Maybe I misunderstood, but I just wanted to point out something funny haha.

    • cindia1977 2 years ago

      i know this is two years later but good luck

  • Christopher Kight 4 years ago

    Oh. My. God! Welcome Back Nancy!

  • Abel Lopez 4 years ago


  • JamieBones 4 years ago

    Any Trig identity videos coming Nancy?

    • StarDagger Rihannsu 3 years ago

      That is in her psychology videos “Trig Identity problems”!

  • Suki Suuuki 4 years ago


  • bravo3 4 years ago

    Thank you. Very helpful

  • Duaa Asim 4 years ago

    I want double and half angle identities of trigonometric functions and sum differences to product and vice versa can you help me?

    • Nick Landry 2 years ago

      we all want a lot of things

  • Grover Smittle 4 years ago

    Please forgive my ignorance—of what use is all of this? And what is a “θ?”

    • PixelCraft Style 4 years ago

      Grover Smittle that symbol means it is an unknown angle, also I have no idea why any human would need this information to complete life but here I am revising it for a test tomorrow so good luck me

    • Competent Thinker 4 years ago

      Trig shows up all over science and engineering fields.

    • Andy Henderson 3 years ago

      I used trig working at Home Depot when a customer wants to have windows which follow the pitch of the roof. They often want to order windows that look like a triangle which has been split in half. If you have the roof pitch, overall base length and distance between the two windows, you can find the size of the smaller window opposite leg as well as use it to find the height of the long and short leg of the trapezoid window.

    • Paul Garcia 3 years ago

      It’s called theta and it is just representing an angle

    • acidicvapor` 3 years ago

      @PixelCraft Style i fell the same way.

  • Karl Scheel 4 years ago

    If Nancy were my math teacher, and I didn’t already know the subject matter, I would have probably gotten an F, because I would have been _so_ focused on her (and distracted by my own arousal), I wouldn’t have been able to devote any attention to what she was teaching. Luckily, I already learned this stuff _way_ back in Grade 10.

    And my pupils would have been _so_ dilated while in her presence, that she would have thought I was on LSD. 😉

  • fan of everyone and everything CHANNEL 4 years ago

    Thank you so much

    • PixelCraft Style 4 years ago

      BTSLOVERS Forever army💙

  • Hayatullah Sayedi 4 years ago

    Thank you Nancy. 🙂

  • Check Mate 4 years ago

    Helpful video but i really need help on advance trigonometry such as proving double angles 🙁 i hope u could help me

  • Jim Decker 4 years ago

    Wow good to see you back on Youtube. Your videos are some of the best math instruction videos on here.

  • txtbts hoe 4 years ago


  • MiKo 4 years ago

    SO you write in reverse? wow

    • Team Reload 2 years ago

      @li Jiu word

    • Mia Clevenger 2 years ago

      @Potassium Chloride she is using a glass to right on and she really using her right hand

    • Sam T 2 years ago

      She’s writting on glass- and the camera is put on the other side of the glass boo

    • Rehoboth Bitege 2 years ago

      @Sam T No, she’s writing backward because English is written right to left. She’s an alien because she can do that. She’s part of the 0.000056 percentile

    • Dorian Sikirica 2 years ago

      Inverse function

  • Kamrul Hassan 4 years ago

    Love you nancy.

  • Zylar Gray 4 years ago

    Thank you Nancy.

  • Maths With Melv 4 years ago

    I love teaching trig. Teachers seem to complicate it SO much and I just wonder how!?! 😫

    • Yute Hube 2 years ago

      Because the longer they faff about teaching the more they get paid and the less work they are doing in terms of brainpower. The same brainpower spread over an inordinately long time period. Driving instructors do the exact same thing.

  • Swift 4 years ago

    Could you please make a video about unit circles and how to solve trig questions using them?

  • Ghostly Yang 4 years ago

    Damn you are hot….

  • Henry Trujillo 4 years ago

    Im not paying attention to the math. I’m paying attention to her lips and her gorgeous face

  • sudipta saha 4 years ago

    hi nancy

  • Purple Dude 4 years ago

    Using these vids to refresh my memory. They are Perfect!

    • Matthew Davies 3 years ago

      Yes, yes she sure is.

  • Competent Thinker 4 years ago

    I like the fact that you take your time; it gives me time to process what I’m learning.

    • MelancholyTea89 3 years ago

      I actually watched it at 1.25 😂

    • capie44 2 years ago

      That. And you don’t have 23 to 31 other little shits distracting both you and her.

    • MEU 2 years ago

      @K. Panther Lmao😂

    • david vivar 2 years ago

      That’s fact

  • World Art Music 3 years ago

    Am i the only one, who thinks she write in backwards? 🤔

    P.s Thank you 🙂

    • Nadiv Lukman 3 years ago

      Isn’t she writing backwards?

    • Aniket Devarakonda 3 years ago

      she’s left handed

    • StarDagger Rihannsu 3 years ago

      @GContreras20bfsla She is in a 6 dimensional pocket dimension that she created through her understanding of Math! It only appears right side up to us, they are actually runes of power!

    • Woodrow wilson 2 years ago

      the video is inverted people

  • Хидежи Охира ! 3 years ago

    I wish i had a teacher like her. Thank you. Greetings from Brazil 🙂

  • Jillian Tauro 3 years ago

    <3 thank you Nancy<3

  • Eric Lovejoy 3 years ago

    syr cxr tyx, I cant spell soh I came up with m own thing.

  • Eric Lovejoy 3 years ago

    are you right or left handed?

  • Max Eisenhardt 3 years ago


  • KHC Online Education 3 years ago


  • Shae Cloud 3 years ago

    where’d our trig sub vid go tho Nancy????

  • Michael Roberts 3 years ago

    Thank you Nancy! Very helpful

  • Thamesh Deodat 3 years ago

    I clicked on this because Nacy is very Attractive 🤙🏽

    • Erin Wolf 3 years ago

      Me too😂😂…she is also a great teacher

  • Babu60 3 years ago

    😁😁😁 ur think is smart and u r too more beauty…

  • Micky Mick 3 years ago

    Wow this is the best presentation I’ve seen.

  • Sh astrophile 3 years ago

    Thank you so much! I missed the lesson in class,but thank god i have found your channel!this is the first time that i understand a math lesson without asking a teacher..appreciated!💜

  • Ozgan San 3 years ago

    sorry i cant

  • Jacob Bassett 3 years ago

    Best math teacher ever.

  • gyarreto 3 years ago

    A bit of constructive criticism i hope,
    is that you would talk faster or more energetically. I found my self skipping a lot cause how slow things are. and maybe also explaining what are sin cos tan initially, like why are they even there. but overall! thank you for the info, it helps a lot!

  • Brian Tollett 3 years ago

    i love math now

  • John Martinez 3 years ago

    Does anyone else notice how at 1:40 she seems bothered by “hypotenuse” not being centered lol, she has a lot of left over blank space, then shes just like fuck it and continues.

  • Jacob Rodman 3 years ago

    SOH = COS
    CAH= SEC
    TOA= COT

  • nasbrain 3 years ago

    I actually miss Nancy

  • Bunnylow 3 years ago

    Im not in trig but your voice is really relaxing when i go to bed

    • Maryam Benabdallah 3 years ago

      lmao yea

  • Be Unique 3 years ago

    please make another q and a video and answer this question…”are you left or right handed?”

  • Spectral Arts 3 years ago

    Smart and beautiful. I am falling in love… can’t… stop…wa…tching…. <3

    • Charlie Haw 2 years ago

      Spectral Arts simp

  • J A 3 years ago


  • BuffaloOnSale 3 years ago

    Gosh youre hot😍😍😍

  • LiL Quacky Duck 3 years ago

    عشكت الرياضيات من وراج🐸💔

  • Religion Ripper 3 years ago

    I can watch you work all day long. God you are the most distracting lady I ever saw. Even if you uploaded a video of you just sitting, i would watch it

  • Rick Lemos 3 years ago

    uau!Wanderfull teacher.Merread with me ???

  • aaron lopez 3 years ago

    oh ! 999 likes My like turn to 1K Oh ! as well valued your knowledge – science !

  • Edgar Marroquin 3 years ago

    So helpful ! thank you so much

  • Denny Law 3 years ago

    I LOVE learning with this woman. She makes it easy and I can focus on the problem. Really wonderful teaching skills.

  • tajinder singh 3 years ago

    Wow, u write reverse.

  • george kalfas 3 years ago

    love your maths!!!!!!!!!!!!!

  • Dehansi Lowe 3 years ago

    It was super helpful but I’d lv if u cd be much faster☺️

  • irgski 3 years ago

    How come my trig teachers were never this cute?

    • Ancilink 2 years ago

      My math teacher is over weight

    • Jim Fowler 2 years ago

      You obviously went to a male-only school!

    • 0 Subscribers With No Videos Challenge 2 years ago


    • LUKAZADIAN 2 years ago

      0 Subscribers With No Videos Challenge how do u have 8k subs with no vids 😂. Good job man. U did it

    • Cup o' coffee 2 years ago


  • Nilesh Pandey 3 years ago

    You taught me a very very nice trick thanks for this video lots of love and respect from india

  • Anthony Joyce 3 years ago

    Smart and gorgeous.

  • Jim Clarke 3 years ago

    What about cani sokit to you

  • Fish Dawn 3 years ago

    I am not sure if I was concentrating on you or the maths. But either way, you rock!

  • StarDagger Rihannsu 3 years ago

    Drop dead gorgeous, intelligent MIT grad, who writes backwards. Impressive, most impressive!

    • asymptotic singularity 3 years ago

      she is using sorcery!

    • Magnum Infinitum 3 years ago

      Actually it’s inverted

    • StarDagger Rihannsu 3 years ago

      @Magnum Infinitum inverse sin?

    • DrHillbillyShow 3 years ago

      *One way mirror.

    • StarDagger Rihannsu 3 years ago

      @DrHillbillyShow One click on a video editing program!

  • Shivaani Jk 3 years ago

    Soooooooooo sllllooooowwwww………….

    • Akshitha Viswanathan 3 years ago

      Shivaani Jk speed up the video

  • David Cooper 3 years ago

    Are you single?

  • James Mclaughlin 3 years ago

    What if adj and hyp are the same lentgh?

    • José Carlos Pérez 3 years ago

      It’s not possible with a right triangle.

  • Just A guy 3 years ago

    You’re left handed!!! I’m left handed!! We should date. =D

    • StarDagger Rihannsu 3 years ago

      I hate to break this to you, she is right-handed, as the entire video is flipped. Did you really think she was writing backwards effortlessly?!

    • Just A guy 3 years ago

      @StarDagger Rihannsu lol yup… my dad can because he learned how to in the military..

    • StarDagger Rihannsu 3 years ago

      @Just A guy Yeah, she looks like she is real JSOC material! It is a flipped image.

  • liquid paint 2 3 years ago

    Nancy I just can’t attention on your classes
    Cuz you are beautiful 😍

    • Joshua Tovar 3 years ago

      Math is beautiful, too. You know?

    • The Happy Hummy 2 years ago

      Or speak English either, huh?

  • Just A guy 3 years ago

    Seriously, How do you know which one is Theta? is it always going to be the angle that is the smallest? Does it just mean that it’s an angle that is unknown?! I am one step above clueless when it comes to trigonometry, but I want to learn all math!! Please help

    • Joshua Tovar 3 years ago

      Theta is any of the two remaining angles that is not the right (90 degree) angle. It is usually given to you by the authority (i.e. teacher, exam question, Nancy, etc.)

  • XLV750RD01 3 years ago

    In German triangles it is alpha, not theta…

  • Scott Powel 3 years ago

    Are you writing backwards, or did you flip the video? Either way, nicely done! Now I should pay attention to the trig you are teaching – your backwards writing hypnotized me!

  • Rich Chel 3 years ago

    I find her a very calming and pleasant teacher! We need more like her in our school systems! LOL!

    • Joshua Tovar 3 years ago

      Unfortunately, our teachers are forced to cover a tremendous amount of material in very little time so they have to rush through it all. I don’t personally think it’s the teachers’ fault but maybe the problem lies within the school system. Just my personal opinion.

  • Ratius Rattius 3 years ago

    This is like amsr stuff…..

  • Herold Lucas 3 years ago

    follow Nancy in calculus ! and 2 you will be find

  • Herold Lucas 3 years ago

    Motion 96

  • Herold Lucas 3 years ago

    you will be fine

  • nazim elhadi 3 years ago

    You re annoying

  • Robert 3 years ago

    Interesting! Da Vinci was also a lefty and wrote backwards.

  • Hh Mm 3 years ago

    Beauty and brain

  • Popeye 3 years ago

    What is the point knowing Trigonometry?

  • thornwarbler 3 years ago

    Thanks for taking the time to explain this its really appreciated

  • chris terroy 3 years ago

    i now know why I skipped this shit in high school ….  laymen terms girl ……   are we building a rocket ship here ?  LOL


    Simply draw a unit circle and demonstrate how cosine relates to x, sine to y, and the tangent line (rise over run 😉 to the circle. Student would learn the relationships, have more than a superficial understanding, and not have to memorize a silly mnemonic.

  • Frank 3 years ago

    Wow smart and pretty !!!

  • Sky Patrol 3 years ago

    I just want 4/5 of a hug.

  • Rashi Nazer 3 years ago

    I too write backwards, I actually do, and people thought I was weird cause I used to be like “Hey I write backwards”

  • Tx Aggie 3 years ago

    Thats all fine and dandy, but you still haven’t told me what sin, cos, and tan are. When I find that the cos of that right angle is 3/5, that doesn’t mean anything to me. its just a number. Can you put some meaning to that number?

  • Just.Observer 3 years ago

    That green marker pen wasn’t the best idea…😉

  • Turjak_art 3 years ago

    Is between her and the cam a glass front? And is she drawing backwords?

  • Mark Patton 3 years ago

    I think she is right handed and she is writing with her right hand on the glass and then the video is playing back negative so it looks like she is writing backwards.

  • Rapture Ready 3 years ago

    Much skill in writing backwards!

  • Jim Flammer 3 years ago

    Would you/did you do a video on finding percentages?

  • Christopher Franklin 3 years ago

    DAMN!!!! You should have been my Algebra teacher in middle and high school….🙂🙂

    • lol lol 2 years ago

      so funny

  • REME 3 years ago

    Wow, …you are beautiful; and smart. Thank you for existing.

    • Qusaybah shah 3 years ago

      damn she fine

  • Ronald Johnson 3 years ago

    trig in 30 seconds … angle looks at adjacent side of right triangle … sally can tell (sin cos tangent) … oscar has (opposite/hypotenuse) … a hard (adjacent/hypotenuse) … on always (opposite/adjacent)

  • paraglide01 3 years ago

    I’m curious, are you writing this in a mirror-style or did you flip the video image?

    • Someone 2 years ago

      It’s not that hard to learn to write backwards, but I think she flips it lol

  • Jonathan Ganesh 3 years ago

    I finally love mathematics. Lol.

  • Chris Wilson 3 years ago

    Hottest math teacher I’ve ever seen 😍

  • Alan Garcia 3 years ago

    she is smart and beautiful

  • Ky Taylor 3 years ago

    can someone please help me with trig I only have three days to finish and struggling

  • Control Man 3 years ago

    You are absolutely amazing and how do you write backwards

    • Mike Earls 3 years ago

      she doesnt

    • Keshav Kumar 2 years ago


  • Kundana Amudala 3 years ago

    Very well explained!

  • masterblimpy 3 years ago

    I had a Ah ha moment back in grade 10, with exactly what you are teaching. Now showing videos like this to my daughter to help her learn. Thanks.

  • Greg Deane 3 years ago

    Now it all seems so easy. I was always confused about which was opposite and which adjacent, but I shouldn’t have been. If you were my teacher I might have got it.

  • Jo Sa 3 years ago

    I passed calculus! Thank you!

    • Clip It! 2 years ago

      Oh wow!

  • Chemistry by Ravi Yaduvanshi 3 years ago

    Plz plz increase your question level@dear nancy

  • John X 3 years ago

    That was a beautiful explanation and I love your backwards writing too.
    However; as it the case with great mathematicians, you didn’t tell us struggling mathematicians what the use of Sin, Cos etc is.
    I have no idea WHY I would need to find out these values or what I can do with them.
    Because of your excellent explanation, I understand what you did and how you did it but, without a purpose to put them to, the information will evaporate.
    Thanks though.

    • Glenn H 3 years ago

      My exact thoughts John X. Nancy please give us lesser mortals an excuse to use Sin,Cos & Tan in real life.

    • Replica 3 years ago

      @Glenn H I’m a little late but, if anyone still needs it, Nancy did another video explaining how to use it here:

  • Ritesh Patel 3 years ago

    I’m wondering if that’s really a glass or some editing software?

  • Lithe Steel 3 years ago

    Too bad you weren’t my math teacher all through high school, I would have never taken my eyes off of you. And I might have learned some Trig while I was at it.

  • chaas seek 3 years ago

    Great teacher

  • Lynne Languedoc 3 years ago

    Corect me if I’m wrong but I think for tangent is opp over adjacent 3 over 4 where as I noticed you have 4over3 = tan which I think tan = 3 over 4 or opp over adjacent = tan .. thank you 😊 for your work please reply.Tony from Canada 🇨🇦

  • Eric 3 years ago

    The reason we do this is to find the angles, sin cos and Tan on their own mean nothing, but you left that part out.

  • Climax !!! 3 years ago

    Thank you

  • narinder sharma 3 years ago

    Hlo mam i m from india plz solve my question problem that find cos35 degree, cos40 degree plz give me solution because I live in villages no souce of education only YouTube so plz rply mam

  • narinder sharma 3 years ago

    I m selected for indian railway driving my 2nd stage exam held march so plz rply mam

  • Charlotte Hu 3 years ago

    This is wonderful. Thank you for explaining it slowly and simply.

  • Muhammad Younas 3 years ago

    I like you r understanding way

  • Dave Deatherage 3 years ago

    Thank you, you explain in an relaxed understandable way that makes total sense.

  • Kristjan Mark 3 years ago

    For writing in reverse, your writing is exquisite!

    • JamieG321 3 years ago

      She isn’t, it’s a mirrored image

  • aan dwi 3 years ago

    Do you date skiny asian guy?

  • Sikndr Ali 3 years ago

    I love u from pakistan

  • Darren Wagenbach Wagenbach 3 years ago

    ⬅ thanks for your help in the sin,cos,tan stuff

  • Donald Fink 3 years ago

    Thank you!

  • Ameyteshwar Singh 3 years ago

    Lol Americans need tricks to learn trigo function and here we Indians are banging our heads on jee advanced questions….

  • Roger didit 3 years ago

    Nancy looks like me, but I’m a dummy!

  • Tenebrousable 3 years ago

    I remember a time when I could calculate triangles without a square angle. But how the calculate an angle out of the fraction? Is it just a comparison to the unit circle that the calculator does? Because that would be…unsatisfactory.

    • Rohan Green 2 years ago

      Tenebrousable – You can use the law of sines or cosines to do this

    • Tenebrousable 2 years ago

      @Rohan Green Ye ok, thanks. But that just makes my problem worse. How does the calculator transform sines and cosines in to angles? What is the calculation that it does? Seems to me like it’s just an approximation of the unitcircle results stored in the calculator. Not an actual calculation.

    • Rohan Green 2 years ago

      Tenebrousable – It’s quite complicated, but I believe that you are correct.

  • Subfocus 3 years ago

    She’s so pretty

  • Ronald Johnson 3 years ago

    she’s right handed..

  • Paul Ladouceur 3 years ago


  • Ines Amato 3 years ago

    At what age do you learn this in the US?

  • Archer 3 years ago

    I had no idea you guys also used SOH CAH TOA in the US (to be fair I thought it was a brazilian thing only, as I normally see in videos here and did in school), left me a bit amazed there!
    By the way, am I’m the only one that gets a serious “Autonomous Sensory Meridian Response” when watching her videos, especially when she talks a bit quiter/softer? It’s really good though, and although it makes me feel sleepy I refuse to accept it also makes me lose a bit of my focus on the content xD.

    Anyhow. Thanks for those videos, Nancy! You’re not only doing an amazing job sharing your knowledge in a very apprehensible way, but also doing it for free.

  • jhony angarita 3 years ago

    pi no es la relación perímetro diámetro pues una circunferencia no es un polígono regular es una curva cerrada

  • jhony angarita 3 years ago

    3.14159… es la mitad de la sumatoria de los lados de un polígono regular de radio igual a 1

  • deemdoubleu 3 years ago

    Sons Of Harlech Come And Harken To Our Anthem

  • Replica 3 years ago

    If anyone is wondering what the functions actually are, rather than just how to to calculate them, they’re ratios. For example, 5/10 = 0.5 is essentially saying that 5 makes up 50% of 10. Likewise, for SIN as an example, it’s basically saying the Opposite makes up result% of the Hypotenuse. In her example of sin, Nancy has it equal to 4/5. This means that the length of the opposite makes up 80% of the length of the Hypotenuse. This of course applies for all the trig functions.

    If you want to know what they’re used for, Nancy did another awesome video explaining it here:

    • Radman 2 years ago

      see the likes in this comment…… NICE

    • Civil Infra Tech 2 years ago

      please subscribe my channel.

    • Namrata Prasad 2 years ago

      Thank you for explaining this!

    • Hardc0re Crypt0 2 years ago

      Your comment is much more valuable than the video itself. Cant be solving math problems without the “WHY?”.

    • Suci 2 years ago

      THANKYOU ♥️

  • Paulo Constantino 3 years ago

    hi Nancy. Can I kiss your feet please ? Can you make a video where you do maths with your toes? thank you !

  • angela misceer 3 years ago

    u did a great job explaining sin cos tan……thanks a lot…

  • Jay Cutler 3 years ago

    madam, you are so cute, I can’t focus on what you teaching me

    • Leonardo Lee 2 years ago

      agree :v

  • Kasey Gonzalez 3 years ago

    Me out loud: wtf is theta?
    Her: theta is just an angle…that’s not the right angle

    I was kinda creeped out by that😂😂

    • rohan bansal 3 years ago


  • Eric Boos 3 years ago

    I want to learn from her.

  • Krishanu Chatterjee 3 years ago

    Voice was very low quality.

  • Le John 3 years ago


  • Wilton Cabral 3 years ago

    Good Job! I love Very much !
    Wilton from Brazil.

  • Nwxxz Chen 3 years ago

    There should be a clear glass between her and her camera and she just flip the scene from left to the right by some video clip software.

  • Transform 3 years ago

    The imagine teaching technique. Thanks a lots

    • Transform 3 years ago

      Her coolness is make an more sense.

  • Dra PvP And More 3 years ago

    12 minute video helped me, instead of my teacher’s 3 Lesson which costed me 3 hour…

  • Inkkles 3 years ago

    yeah but what is sin?

    • Warc Arden 3 years ago

      Inkkles its a circular(aka trigonometric) function that takes in an angle as input and gives a ratio as output. Its defined as the ratio of the opposite side to hypotenuse in a right angled triangle

  • 000 ooo 3 years ago

    i am BANGALI student .

  • Lavi Mac 3 years ago

    ure great tks

  • ChipsAhoy 3 years ago

    This video has taught me more in 12:30 minutes than my math teacher in 6 hours. Thank you so much! But for some reason i only found this video the night before my unit test.

    • u235u235u235 2 years ago

      that’s because you’re learning something (or something half learned before) for the second time. you’ll find when you go back to relearn something you only partially learned that it seems as though the second time around the teaching is better because you’re closer to “getting it.”

    • Twilight_Evening Bluh 2 years ago

      Maylin Quinn me too, currently trying to learn as much as I can

    • Nick Thomson 2 years ago


    • Uncle Joe 2 years ago

      Uh huh huh huh huhuhuh – you thaid “UNIT” uh huh huhuh

  • Ayanast Bayanast 3 years ago

    You are Darin !
    Would you teach basic differential equations.

  • Knjal Sarkar 3 years ago

    so sweet vioce

  • Kris Kollar 3 years ago

    super hero!!!

  • Morgan Miao 3 years ago

    Wow, she can write backwards….

  • Jonney Silver 3 years ago

    What if we want to measure the 90 degree angle there?
    The opposite is the same as the hypothenus and two adjacents !

  • Fatma K 3 years ago

    Super helpful but raise ur voice a bit☺☺☺

  • Chris 3 years ago

    I LOVE this video. I have needed you to record videos that I can use in Geometry class for the longest! Thanks!

  • murat pehlivan 3 years ago

    trigonometriyi bu anlattı da biz mi anlamadık

  • Lillie Rose 3 years ago


  • Chelsea's Vlogs 3 years ago

    Pleasee do more of trigonometry because you had helped me study a lot for my pre-calculus class & so far I been passing with 90s

  • lordofjango 3 years ago

    I am shooter want to know where is my impact bullet drop on x range to know should i adjust my sight or not. I remember i study how to calculate this but not sure. Here i am…with cutes math teacher on youtube. Now i realize i am not suck on math. Just because my booring math teacher was i cant undertand what he says lol.

  • Certified Ugly 3 years ago


  • Aussie E-piper 3 years ago

    31 years ago, I spent a whole school term trying to understand this. I never could. Now, after 13 minutes, I do.

    • jatin karkera 2 years ago

      Bruh in India we say it OSH-ACH-OTA

    • Reliez T 2 years ago

      That’s the age of maturity.
      When you get older, the level of thinking improves.
      Not to blame on your middle school teacher, hope she had done her duty.

    • Zaine Reo 2 years ago

      Where did you go during the class? 😆😆😆

    • Adewole Onibokun 2 years ago

      @Aussie Epiper Wow you must have been really stupid back then.

    • Civil Infra Tech 2 years ago

      This video show you to calculate angle just with measuring tape and without 3,4,5 method, if you like this video then i deserve one subscription from you please.

  • Gangastar Games 3 years ago

    Nancy please how the hell can u give a lesson by writting from the right to the left???
    Ur unbelievable
    Thnx for all the videos that u made
    It helped me a lot. 💗

    • Desert Forge Knife & Tool 3 years ago

      Thats easy she is LEFT HANDED….LOL

    • Gangastar Games 3 years ago

      @Desert Forge Knife & Tool 😂👌

  • Matt Hilgaertner 3 years ago

    Hi Nancy. Could you please post some videos on how to graph all 6 trig functions, including asymptotes, periods, phase shifts, amplitudes, etc.? That would be awesome. Thanks!

  • Shibli Ziadeh 3 years ago

    It’s funny how some comments are about Nancy’s ability to write backwards. She doesn’t, because of using a mirror so we can see and she is not obstructing the view. Simple example, on the ambulance, as you are driving, you see the word perfectly from your back-view mirror. But if you got out of your car and actually looked at the word ambulance, you will see that words is spelled out backwards. So, it’s the same concept.

  • Hassan Singano 3 years ago

    I don’t think about if I can understand this topic because I used my time to watch her instead of what she is teaching, hahhhhhh

  • Kitti Kat 3 years ago

    What if the triangle dosent have the theta🤔😑

    • Warc Arden 3 years ago

      Kitti Kat theta is the angle between 2 sides, its either given or you have to find it in basics like this

  • Jatex 3 years ago

    Bruh moment

  • SplinterHDCombat 3 years ago

    your mirror writing is a million times better than my best calligraphy

    • Jaeson Blaze 3 years ago

      Dnt u think the video is reversed?

    • SplinterHDCombat 3 years ago

      @Jaeson Blaze now I have to know which it is , youre likely right

  • سعيد شخبوط 3 years ago

    يعطيتس العافية يانانسي عجرم

    • Ksa LOVE 2 years ago

      سعيد شخبوط ي رقال 😂😂😂💔

  • Dave V 3 years ago

    Thank you! You explain these concepts very clearly!

  • CamiloSanchez1979 3 years ago

    I’m in love

  • Noureddine CHAIB 3 years ago


  • XxQueenXX XxxX 3 years ago

    Its a lot of info, but its great help, thanks

  • On ig 3 years ago

    She writes neater than me but she’s writing backwards 😂

    • Ass ho 3 years ago On ig , jokes on you she did a mirror image. Witch means she was not writing back words

  • Qusaybah shah 3 years ago

    nice vid

  • Dale Erwin 3 years ago

    But I do like math. Does that mean I can’t like your video?

  • Olives Olive 3 years ago

    Thank you 🙏🏻
    Love watching your videos!
    So helpful

  • Mr. Singh 3 years ago

    I cant forget to like because writing right to left is not that easy. 😁😁 I knoww. A lot of hardwork. Lov u mam. U saved me. 😣😣

  • monte751007 3 years ago

    I am super bad at math and I always wondered what is this sin cos tan theta crap, until I see this video. I totally understand this concept and feel very confident. Thank you so much for this video. Despite being very intelligent you are absolutely beautiful. Cheers.

  • Tony Learner 3 years ago

    Thank you, Nancy, for the marvelous teaching that you do. And now my favorite equation of all time as follows … Brains + Persona + Beauty = NancyPi

  • umashankar Kumar setu 3 years ago

    Waw not knowge

  • Mohit's Area 3 years ago

    Luv watching ur vdio😊☺😊☺

  • Ian Cruz 3 years ago

    how can she write from rigth to left !!!, by the way thanks for the explanation

    • Dark Angel 2 years ago

      Ian Cruz she wrote normally and flipped it in editing

  • MDU NTR 3 years ago

    I watched these videos so much it helped me master Physics… Thanks…

  • NotMarkKnopfler 3 years ago

    But what *ARE* They? You’ve omitted the most fundamental point. There’s no point describing how to calculate them if we don’t know what they *represent*.

  • Emperor Sheev 3 years ago

    Bruh u pretty

  • Gerald Brooks 3 years ago

    Thank you so much!! I barely got through algebra in college and have only used basic arithmetic since then. Now that I’m retired, I am determined to learn the fundamentals of trigonometry so I can finally understand how, after “shooting the stars” with a sextant, accurate timepiece, and various navigational publications, my fellow quartermasters and I were able to find our ship’s position on the high seas. I appreciate your calm, unhurried teaching style and will be watching all of your videos. Thanks again!!

  • Princess Ginez 3 years ago

    I like how simple or the strategies of yours is very easy, that’s why I found it easier to understand. Thank you so much for creating this video.

  • Santino Oliveira 3 years ago

    Thanks NancyPi

  • Robert Alvarez 3 years ago

    This is awesome!👍

  • abou ali 3 years ago

    Perfect 👌

  • Frank X 3 years ago

    That really did help! Thank you!

  • Mr Watson 3 years ago

    Brilliant… THANK YOU : )

  • simran Meena 3 years ago

    Mam, you are beautiful and smart..

  • Kshitija Jadhav 3 years ago

    Love u from India

  • yugioh deck profiles 3 years ago

    speek up

    • The Raddest Scorpion 3 years ago


  • Horom Limited 3 years ago

    great, super funny lessons, tx Nancy

  • JAG 0937 EB 3 years ago

    don’t write on inside of my computer screen you dumbass

  • JAG 0937 EB 3 years ago

    hippopotamus side

  • realtoast 3 years ago

    I have no need to know any of this in my daily life. But I’m watching every one of your videos anyway, as I’m actually understanding them and can picture the utility.

  • Spurii 3 years ago

    Brilliant! Very easy to follow – Clear and Precise speech – Nice steady pace – perfect simplicity – I have confidence in this subject in less than 15 minutes – THANKS Nancy XX

  • Ravi Sivalingam 3 years ago

    Nancy marry me… ha ha ha… If you had a guitar in your hand … Alannis Morissette in the Flesh … I really enjoy your videos.. they are verrrry informative and clear … thank you

  • Robert Geddis 3 years ago

    Helped massively, thank you

  • pantyhose babes and metal 3 years ago

    sure brings back memories babe.i was good at these in school.students ask me advice,teacher was to busy. i didn’t think of it again,till now, ,still remember

  • Xboy Dubose 3 years ago

    But what about equations like sin(90) or cos(60)? Those aren’t triangles and don’t have a Hypotenuse, Adjacent, or Opposite side.

  • Kennith Lambert 3 years ago

    Your theta example explained a lot. Teaching myself trig for some time but somehow I never quite got the whole theta thing. Thanks.

  • Deepak lovely Kumar 3 years ago

    I have never seen such a beautiful mathematician in my life…

  • Steve Hines 3 years ago

    Hi Nancy,
    You did such a nice job of explaining how to get the six basic trig functions. If I were in your class, I’d never miss a day.
    I think you may like something I came up with in first year college when I thought trig was so poorly explained…
    Also an analog calculator for basic math, and/or use in third world countries… .

  • ElectricShock 3 years ago

    Thanks for the Basic lecture.
    i promise coming here frequently~

  • Harsh Vardhan 2 years ago

    Damn she’s actually writing the mirror images of letters and numbers

  • Raul D´Empaire 2 years ago

    The moment you realize Angeline Jolie is your Math instructor….Thank you, a very simple straight-forward explanation.

  • vsp 2 years ago

    Ok i know the formulas for it… but what does sine actually do?

  • Jo Brill 2 years ago

    Good stuff Nancy, thanks.

  • Drew Durant 2 years ago


  • Hey there 2 years ago

    I have just watched the entire videos without getting anything .
    Actually,I were lost in your beautiness .

    • Luis V 2 years ago

      Her voice is asmr

  • Manivannan D 2 years ago

    Everyone see this video in 1.25x speed.


    I love you! You are so beatiful! Let me marry you!

  • Braiden Kreller 2 years ago

    Will you be my tudor?

  • Lily Donlon 2 years ago

    I’m in 7th grade and I don’t know what I’m doing or why I’m here I’m just bored…

    • ღ DJ PRO ღ 2 years ago

      lol me too
      but I am 8th grade

  • Be Unique 2 years ago


  • Anil Joseph 2 years ago

    I wish this was communicated this way 3 decade ago… Cheers!

  • Jay-Pee Phillips 2 years ago

    So calmly expressed with a soft teaching voice that enables one to grasp. Thanx and much appreciated Nancy!

  • Dr. 2avAge 2 years ago

    Easier than i thought

  • Surinder Kumar 2 years ago

    thanks… your video really helpfull to me

  • owais qureshi 2 years ago

    only black color is recommended!!!

  • Andy Song 2 years ago

    are you writing in the opposite way?

  • Hitman sniper 2 years ago

    Sorry ur beauty distracted the teaching

  • yahya ahmed 2 years ago

    DO i have to wear headphone to hear you Nancy…

  • yahya ahmed 2 years ago

    Dad: Are you stupid can’t you solve this
    ME: Shit i hate Math

    Nancy: Hi guys I’m Nancy
    ME: I could be a mathematician!

  • Balpreet Singh 2 years ago

    i have a doubt which is very complicated
    can i meet you
    pls or can i get ur any contact so that i can call you

  • Lucid Dreams 2 years ago

    Be my arc tangent

  • Center Minded 2 years ago

    Brain hurts, but I will persevere. Thanks for the lesson.

  • uzair muhammad 2 years ago

    i am really Sorry i couldnot focus on 2 beauty simultaneously . 1 the beauty of ur teaching 2nd u ur self

  • JOHN SASSER 2 years ago

    Thank you for the videos NanciPY. They have been great because of the slowing moving explaneations.

  • Mohd unnati Ashraf 2 years ago

    Video ilike it

  • Nightfall ASMR 2 years ago

    Amazing explanation. I saw this crop up in a programming example. It was an animation of the Earth circling the Sun. In the code it used sin and cos to determine where to draw the Earth. I didn’t know anything about it so I searched and found your video. Really cleared it up for me. Thanks!

  • Rusty 2 years ago

    I think I would fail her class on purpose so i would have to retake it lmfao

  • ahmed elahl 2 years ago

    Thanks alot that helped me so much.

  • Madison Negley 2 years ago

    I’m doing Trig in Geometry, So this is very helpful, thank you.

    • Joaquin Rojas 2 years ago

      Same I’m a freshman in highschool

    • Jessica Byersmith 2 years ago

      Same and it’s confusing

    • Madison Negley 2 years ago

      Yes it is, I’m a sophomore but I still find math extremely difficult to try to accomplish

  • João Vitor 2 years ago

    Não entendi nada, parace ate que esta em outra língua!!

    • Gabriel Chew 2 years ago

      Que isso jovem? Parece não , está en outra língua kkkkk , é inglês meu amigo , procure em português que você vai entender certinho

  • Endless Knowledge 2 years ago

    Definitely weed🤫

  • Adarsh Malviya 2 years ago


  • Hatem6s 2 years ago

    thanks habibti, very helpful. i will make du’a for u hope u marry a halal husband

  • Gavin Adamire 2 years ago

    your triangles are scalene and not right

  • Andrew Gutierrez 2 years ago

    Thank you Nancy the right handed teachers make me feel like I’m doing it wrong now I know I’m not thank you

  • Anthony Gato 2 years ago

    I know the way u write backwards.

  • Persian Guy 2 years ago

    Nancy makes me love math

  • Eden Molinar 2 years ago

    Oh my the volume is really low on this very excellent video

  • JOHARNOLD GG 2 years ago

    MULTIPLY 8 X TAN(34 DEG.) =5.39606813474

  • JOHARNOLD GG 2 years ago


  • Bobby Poly 2 years ago

    Thank you so much you are a blessing to the youtube classroom!!

  • Amber Grant 2 years ago

    Great videos. Thanks

  • Film trailer zone 2 years ago

    How beautiful mam

  • Guru Prasad 2 years ago

    thank you

  • Richard Head 2 years ago

    Marry me Nancy 💜
    And we can make beautiful math together 📈

  • physics evangelist 2 years ago


  • Ariwan igelisias 2 years ago

    I love sexy teacher

  • Alberto Perez 2 years ago

    Best videos about trigonometry I’ve seen

  • ilia 2 years ago

    thanks alot. it was so helpful 🙂

  • Абдусаид Тореев 2 years ago

    Здравствуйте Хороший видео но без перевода не понимаю что вы говорите сделайте русский перевод пожалуйста Спасибо заранее

  • Timothy Guan 2 years ago

    SOH CAH TOA is helpful

  • Lethabo Makitla 2 years ago

    How does she write like this?

  • Jacob Alrin Ragaza Ong Amboy 2 years ago

    Damn 😍 can i have ur number? 🙂

  • jawnee logik 2 years ago

    I woke-up this morning with a burning question on my mind: How to find the sin of a right triangle? Now I know, but the other burning question remains — why would I need to know that? That answer was not provided by this, otherwise fine, video

    • Dwain Blackwelder 2 years ago

      There are many areas where this can be used. Bending and offset angle in conduit: sinΘ = opp/hyp. if Θ is 30 degrees, sinΘ =.5. If you use the cosecant of .5, which is 1/.5, you get the answer 2 which will be our multiplier. Using the cosecant allows you to multiply instead of divide in the following example. Say your conduit needs to rise 6 inches from the current surface it is mounted too in order to follow another surface that is higher up. The 6 inch rise needed is equivalent to the opposite side. In order to rise 6 inches, the hypotenuse needs to be a certain length and depends on the angle you use. If you bend your first 30 degree angle, where do you bend your 2nd angle? The answer is the distance of the side opposite x our multiplier which is 2. Therefore the distance between bends is 6 inches x 2 = 12 inches. A lower angle such as 10 degrees would require a longer distance between bends in order to reach the same 6 inch offset as described above. Other uses would be determining the length of guy wires needed to secure a tower if the angle of each cable needed be secured to the ground at a 60 degree angle. How about the rise of roof trusses for a house. Trig allows you to calculate the truss lengths and the angles that need to be cut for a particular roof pitch. Hope this helps.

  • vijay yadav best videos 2 years ago

    Lovly maim

  • Waldo Chavez 2 years ago

    OH HELL YES!!! I feel smrtr already

  • sienna black 2 years ago

    I love how you take things at a steady pace, and explain it thoroughly. It really helps me learn. Also!! The setup is so pleasing and easy to learn from 🙂

  • david lingaard 2 years ago

    Nice video, i tried this in auto cad and it worked

  • SJKlavier 2 years ago

    Beautiful in every way!

  • Freedomofexpressi100 2 years ago

    In the machine shops, they use a lot of trigonomtery because we use machines (CNC and conventional) to do parts for radius , cut specific angles………..

    • Emodude 2 years ago

      Freedomofexpressi100 I’m in a new internship at an engineering firm and I still haven’t taken Trig. Having an application helps me understand it a lot!

  • Nimrah Ellahi 2 years ago

    I wish you could be my teacher or were my teacher!!… Sigh

  • Trappist1964 2 years ago

    Thank You. I am using this video to prep for trigonometry course.

  • Trappist1964 2 years ago

    i also think you are much more attractive than my math teacher. your explanation were easy to understand.

  • Ved Prakash Chaubey 2 years ago

    You are hot.

  • Spencer Fazzio 2 years ago

    Can I go to the bathroom?

  • Gabby 2 years ago

    She reminds me of my Math teacher…

  • محمدعلي عماد ألامين 2 2 years ago

    Good teacher

  • AZFARUDDIN MIDDYA 2 years ago

    how r u Nancy ?

  • abdul latif 2 years ago

    what cream do you use for your skin? my girlfriend next to me wants to know. 🙁

  • Yeontan's Eyebrows 2 years ago

    Oh god maths English hurts my brain. I should really learn more complex English and not just the really casual conversation stuff so that I could learn from videos like these 🙁

  • Donny Helvey 2 years ago

    Where were you 1981 in my math class to teach me? That was so well presented!!

  • say something 2 years ago

    sorry to say this but the pens were not very clear

  • Vijoy winson 2 years ago

    Are you on the other side of the room writing vice verse or writing a diff Lang ¿

  • Risuu 2 years ago

    How do you write??? Like do you write in mirror?? Thats gotta be tough XD

  • Slimboyfat1979 2 years ago

    You are an excellent teacher. If more math teachers were like you people wouldnt be so afraid of math..!

  • ToadSprockett 2 years ago

    Thank you for making this so simple and clear, I barely made it out of college algebra and now find that I need a solid base of trig for development. You definitely have the gift of teaching, again thank you for sharing…

  • Terror Channel 2 years ago

    Thank you so much

  • Ethan Kotekar 2 years ago

    My teachers try to make it complex but when you watch on YouTube it’s like year 2 maths

  • Kanishk Jain 2 years ago

    Thank you so muchhh!!!!!!!!

  • Dante Garcia 2 years ago

    Man how is she smart and beautiful

  • rose dantas 2 years ago


  • Twilight_Evening Bluh 2 years ago

    How would you solve a right triangle without an acute angle ?

  • Lake Tahoe Blue Faces 2 years ago

    I’m brushing up on trig for a metal stretching skill set on a machine and DAMN I would be willing to learn ANYTHING from this woman!!! Talk about keeping my attention lol 😘💯🔺️

  • Aminu Shehu 2 years ago

    Nice work

  • Harshavardhan Nandi 2 years ago

    All silver teacups

  • Maaifoedie De La Rey 2 years ago

    This video has received 215K views, but only less than 6K likes. Come on people, really ?!

  • Anupam Yadav 2 years ago

    🙏thank you

  • HGR693 2 years ago

    Nice session ! Don’t give up !.

  • Fadel Sudrajat 2 years ago

    I love you

  • Safiyyah Lyle 2 years ago

    I finally understand it 😭🥳

  • adam 2 years ago

    She is hot.

  • Raven Renders 2 years ago

    Can you become a professor at my college?

  • manpreet singh 2 years ago

    Hello maam

  • Dan 2 years ago

    I understand everything that was taught in the video but some one care to explain the function of Sin Cos and Tan? What is the fraction representing?

    • Kellan Larson 2 years ago

      It depends on whether you are trying to get side lengths or angles, and each function helps you to get the values of different sides or angle with the information you already have

  • Benafsha Shakari 2 years ago

    Thank you!

  • Samantha Smits 2 years ago

    This was the first time ever that I was able to grasp what was going on! You are awesome!

  • chris nance 2 years ago

    Do you have to write everything backwards for us to be able to see it right way round???

  • i have 2 dads 2 years ago

    omg she is so hot im 15 btw

  • Jack Boi13 2 years ago

    Ya ya I get it she’s beautiful but how the hell does she write backwards😂

    • Shawn Decker 2 years ago

      The video’s mirrored. She’s actually writing with her right hand

    • Someone 2 years ago

      It’s not hard to learn to write backwards. I learnt in about a week!

  • Zaldy Santos 2 years ago

    Very good well teaching

  • billg521 2 years ago

    I thought I was watching Angelina Jolie teach trigonometry…. Nancy could pass for her twin sister!!!

  • nothereforlong 2 years ago


  • Tjazzifer 2 years ago

    watching this just before a math test, Soh-Cah-Toa will save me lol

  • Mawz M. 2 years ago

    This is useful and all, but did nobody else notice she had to write everything backwards?

  • John Vandersall 2 years ago

    nancy what are you doing on u tube

  • C T 2 years ago

    Great explanation!

  • Nico Nicoson 2 years ago

    Studying architectural technology and have learned more in 3.14 minutes watching your vids than months of math class

  • P T 2 years ago

    How can you figure out what your legs are when you are only given a right angle with no theta?

  • UPWork Riyas 2 years ago

    No words madam. Thanks alot.

  • Michael Jetnikoff 2 years ago

    Hi,please use graph tan xy,tan xz, tan yz ,see true function structure ,bliss,thee,XAMBUNJILOM

  • Slowed Tracks 2 years ago

    soh cah toa
    suck a toe 😳😳

  • Jake Boelter 2 years ago

    Extremely helpful, thank you.

  • cringeworthy productions 2 years ago

    i learned trig in 12 min lmao. teacher has been spouting nonsense. ty :)))))

    • Someone 2 years ago

      What grade do we learn trig? I’m in 9th and I taught myself trig from online but my teacher keeps telling me I don’t need it this grade… All that effort wasted… Can’t wait to actually use it in school!

  • Killa stuff 2 years ago

    One thing I keep thinking about is how are you writing like that on glass. Is this some photography trick or did you learn to write everything inverted?

  • Aadhithya Kumar 2 years ago

    Great video, holy crap the first 2 classes I count figure it out

  • Zeeba Ghlom 2 years ago

    Math is the worst subject ever so confusing but once you learned you get

  • William Flanagin 2 years ago

    This is truly an awesome review for this subject matter. Thank you

  • R KARTHIKEYAN 2 years ago

    U r so beautiful

  • Cooper Bingham 2 years ago

    she seems like she’s being held captive and being forced to do this

  • Georgi Georgiev 2 years ago

    I still don’t what is the rule for defining which angle is theta. Which angle is the theta angle in an equal sided right angle triangle for an example?

  • Frank Thompson 2 years ago

    You make learning fun!

  • Alyssa Mohammed 2 years ago

    She looks middle eastern

  • Abbey Lo 2 years ago

    This really really helped me understand it! Thanks so much! Your pace at which you go is perfect because it allows me to take my time in understanding the material.

  • arklanbk 2 years ago

    iv bookmarked this video

  • MINI 2 years ago

    Why was this not possible for my math teacher to make understandable in two whole years, when you made it possible to understand in such a short time?

    Impressive and thank you.

    • flowerylisi _ 2 years ago

      jotaro~kun? 👀

  • Daniel Clancy 2 years ago

    Lmao how can I not like,
    shout out LI, NY!

  • Primo Benavides 2 years ago

    Why doesn’t Pi equal 3.3333333333333 vice 3.1416926589793? A difference of only 0.1917406743507 Respectfully Out!

  • Emo Bassist 2 years ago

    Damn if i had her for a teacher is get straight As for sure

  • Âdan 2 years ago

    Everyone here is a simp

  • isaac gonzalez 2 years ago

    Man I wasn’t even paying attention I just wanted to see u talk 😳 u pretty

  • john pew 2 years ago

    Every time I hear SOH CAH TOA, I think of Squidward saying “Krakatoa!”.

  • disleksiekdudelbot #1 2 years ago

    Thanks for the help I’m in a German integration class and I missed a lot of math work and you have help me allot

  • Depeche NODIR 2 years ago

    How are you writing vise versa ?

  • BRIAN CHEN 2 years ago

    oh my gawd i lost

  • Jubi Khan 2 years ago

    Thanks. For giving me a explanation about it.

  • Jac Ryder 2 years ago

    Interesting… in the UK we are just taught: if you don’t have the angle, “invert” or find the “inverse”, which is sin OR cos OR tan, to the power of -1, of the angle. We don’t speak about csc, sec or cot.

    • munis varan 2 years ago

      Yea man,what a great teacher 👍

  • Jac Ryder 2 years ago

    We also don’t use Theta, we just write ‘x’

  • Tamsyn Slabb 2 years ago

    Thank you so much I was so lost

  • Jim Fowler 2 years ago

    Trig, Vectors, and Calculus are my favorites……..excellent video and teaching, thank you very much!!

  • Roberto Eduardo Madrazo Estrada 2 years ago

    Outstanding video and very well explained. Outstanding narrator I might add.

  • munis varan 2 years ago

    Amazing teacher,if i had study well 31 years back,might score good,Now this brilliant teacher guide me back well.Thank you teacher. 👍🙏👌✔💎

  • Teenage Gamer 2 years ago

    It must take some skill to write backwards on glass like that
    Actually wait they could just write it normally how they see it then flip the video too

  • Jeronimo Oliva Velez 2 years ago

    Great Explanation! Thanks!

  • Tyson Subban 2 years ago

    Thankyou Thankyou very much

  • MaddoxInc 2 years ago

    Can we get someone ugly to do this? I have to keep restarting, I keep loosing focus

  • A B 2 years ago

    If she taught “strip” Math, suddenly all the boys who are “bad at Math” would become A students 😛

  • Fish Dicks 2 years ago

    When I realize her backwards penmanship is far greater than my regular penmanship 🥺

  • Waliullah Gazi 2 years ago

    I like ur note

  • Shyamali Dewry 2 years ago

    The trick is awesome

  • ScorcherMaster 1 2 years ago

    I just realized, she’s writing this entire thing backwards. That takes talent and practice.

    • Kalimari Zali 2 years ago

      how is she writing in the air?

    • broke Engineer 2 years ago

      @S H what the?😂. Are you serious

    • FireLord Zaki 2 years ago

      No nigga she put her thang down flipped and reversed it

    • Muhammad Grill 2 years ago

      @S H Bruh, You just made humanity lost 100000 braincells

    • Muhammad Grill 2 years ago

      @Hockeyqs2 Bruh, I used to be left-handed, I didn’t right backwards… -_- basic knowledge.

  • ELLIPSES Is Power 2 years ago

    I had no need for learning trigonometry as unfortunately I’ve done foundation for maths for the past 2 years but it’s actually alright…

  • Da_Potato_Power ÙwÚ 2 years ago

    Bruhhh this is so clear!!!

  • Da_Potato_Power ÙwÚ 2 years ago

    I know I’m only grade 5 but I understand this!!!!!!

    • cindia1977 2 years ago

      What a clever potato you are!)

  • Electrifying Mind's 2 years ago

    You are beautiful

  • Sai Mathematics Orientation Education 2 years ago

    See Sai mathematics orientation education for easy method and song

  • Blake Alexander 2 years ago

    Although she sounds like she has the IQ of a McChicken I actually understand it now

  • Ddstairclimber 2 years ago

    please make a video on derivative applications for business!

  • Can Tezel 2 years ago

    how do you right backwards so well?

  • Mike Young 2 years ago

    All I’ve ever used sin and cos for is to plot x and y coods with movement for games. It’s lets you move at an angle at a speed and plot the new x/y coods. I never knew why this works though.

  • Salem Ezeaku 2 years ago

    Wow…. easiest way to learn

  • jeff ghant 2 years ago

    Where were you in 2008 when I was failing trigonometry miserably?

  • Sandra Iwundu 2 years ago


  • Jahongir Mirhoshimov 2 years ago

    amazing love her pedagogy, how you teach, you re just amazing, you were born to be a teacher

  • Jahongir Mirhoshimov 2 years ago

    i cant express my gratitude in words just amazed.

  • An Idea 2 years ago

    Only for nanci you stole my heart 🙈😍

  • Ivan Quirola Espin 2 years ago

    You helped me out found this vid very useful 👍
    Your very cute btw

  • Telepcanin 28 2 years ago


  • Alexis Bouchard 2 years ago

    This woman is brilliant! 🙂

  • paperscissorhands 2 years ago

    how’d you learn to write in mirror image?

  • Vivan Joshi 2 years ago

    Waste of time

  • Navya Shah 2 years ago

    this is not even part of my course but it is intriguing , you are a great teacher. thanks!

  • theko Maenetja 2 years ago

    I was interested until you complicated things by introducing sec, csc whatever.

  • Henry Phan 2 years ago

    You are a great teacher. I use a partial lesson for my kids

  • DARKREDHAYABUSA 2 years ago

    Nancy Pi: “You don’t have to like math but you can like my video”

    Me: Done

  • Joseph Broemeling 2 years ago

    You are a God send, I was desperate to find someone who could help me learn Trig so I can take the Classical Learning Test, and your teaching style is easy to understand and thorough. Thanks a million. Also, you are so beautiful, if every woman looked like you this world would be a better place.

  • Stafford Nelson 2 years ago

    muchas gracias!

  • JackM 2 years ago

    Literally better then my teacher I learned more from you then my teacher for the past few years

  • orlan sison 2 years ago

    Thank you for sharing. Your not just beautiful bit also passionate teacher

  • Dineth Demuni 2 years ago

    I want her as my teacher😍

  • ReeseGod456 2 years ago

    what if one of the numbers is a variable?

  • Ben Vredevelt 2 years ago

    Pick your “Perks”? 🙂

  • Sarthak Chaturvedi 2 years ago

    Plz make a video on sin cos theta sin cos tan 🤒🤒

  • Daniil shyrov 2 years ago

    i am confusion


    love I t

  • squishie kitty 2 years ago

    This is so useful during quarantine. My teacher stopped teaching and its just book work so you’re so helpful thanks.

    • Lonewolf 2 years ago

      @Gladius Gaming i couldn’t agree man, I get the same thing from sch too

    • Gladius Gaming 2 years ago

      @Lonewolf yeah during quarantine. Personally I find it difficult to focus or learn

    • Lillian Heiberg 2 years ago

      my teacher didnt stop teaching but he became worse at explaining than he was in class
      and he wasn’t very good at explaining in class

    • 6daemonium crowley 2 years ago

      I don’t understand why government pay teachers like the one you have. He or she don’t teach anything but she is getting paid, that’s a waste of tax money

    • Gladius Gaming 2 years ago

      @6daemonium crowley its not just them, its also the departments, in Australia, theyre quite disorganised and this baffles me that YouTube does much better as a learning platform but i agree with you

  • William Meng 2 years ago

    Guys! I don’t think she writes backwards! I think she just mirrored what she was writing. check out the channel mahalodotcom. Then she also writes backwards. Another example: Jimmy Chang on eHow. I don’t think there are that many people that can write in reverse that easily.

  • Benjamin Rice 2 years ago

    Trigonometry is Dis Cos Tan

  • Manuel Florencio 2 years ago

    Your good! lectures are simple and very easy to comprehend. Pls give more lecture series.

    • IshaMaths Tea 2 years ago

      I just posted a video about calculating trigonometric without using a calculator…… I hope it’s helpful….

  • Kvothe Newarre 2 years ago

    I’m having a terribly difficult time focusing beyond how attractive you are. My goodness.

  • TheBestTv 2 years ago

    круто и понятно, right ?

  • Sparky McFarlane 2 years ago

    I think I’ve been hypotenuse-tized.

  • mohammad yousaf 2 years ago

    You made it easy no more fear of maths…..😂

  • rammya bandara 2 years ago


    • IshaMaths Tea 2 years ago

      Hello fammya, I just posted a video about calculating trigonometric without using a calculator…… I hope it’s helpful….

  • J Khan 2 years ago

    Thank you although I can’t concentrate on learning now.

    • IshaMaths Tea 2 years ago

      Hey J, I just posted a video about calculating trigonometric without using a calculator…… I hope it’s helpful….

  • kenneth chigali 2 years ago

    Thank you very much Nancy for excellent lectures .And can easily grasp concepts …You are simply the BEST.

  • MR 々͜͡AHMED 2 years ago

    Are you married

  • MR 々͜͡AHMED 2 years ago

    خرب حظي ماتجين درسيني والله اصير الخوارزمي

  • Josef Finn 2 years ago

    Very good! Thank you.

    • IshaMaths Tea 2 years ago

      Hye Josef, I just posted a video about calculating trigonometric without using a calculator…… I hope it’s helpful….

  • Jeruld Ablang 2 years ago

    next time use bikini its more better to listening in 12:24 mins

    • Jeruld Ablang 2 years ago

      @IshaMaths Tea Bruhh you spell my name wrong

  • Pahanin 2 years ago

    Omg she’s got massive talent

  • Raffy Mendoza 2 years ago

    If your going to be my teacher, I’ll come back to school 🙂

  • The Hunt Rock Band 2 years ago

    This helped me a lot! Thanks!

  • MetheNugget 2 years ago

    I was home from school two weeks before my school put everything online, and that was when I assume they were teaching basic trig like this. So when I saw more advanced stuff on our google classroom I was extra confused. In short, thank you for this video, it helps a lot 🙂

  • ilovepugs123 2 years ago

    you look like angelina jolie ur so pretty!!!

  • Khanderao Jogdand 2 years ago

    Thanks for converting geometry from a difficult one into an interesting and easy to my children

  • Flow Baby 2 years ago

    I actually have an 8 inch cos

  • Mashal Sabarad 2 years ago

    How to identify what is theta

  • Ivan Grbović 2 years ago

    You are beautiful 😍

  • Na Zombie 2 years ago

    Great lesson!!! I am glad I found your videos I never took trigonometry and high school so I have just been teaching myself by watching youtube videos and taking notes. I want to thank you for bringing up those different kinds of right triangles because the third one you drew use to make it difficult for me to understand what title was what but you cleared that up perfectly.

  • Roni Matemática 2 years ago

    Like aqui do Brasil!

  • SHAME Yt 2 years ago

    That kind of teaching is actually hard the board is in our front now she had to do reverse writtings

  • SHAME Yt 2 years ago

    2:58 might be the start

  • Sebastian Mancilla 2 years ago

    what if I’m not given the values of the triangle? 🙁

    • Alex 2 years ago

      then you can’t find the sin cos and tan

  • Dejan Misic 2 years ago

    You’re and beautiful and smart, congrats! Not often to see

  • Davvo 2 years ago

    my teachers are annoyingly difficult, they dont tell us to find the “sin” or “cos” they just say find the angle

    • Rohan Green 2 years ago

      Davvo – You find the angle using inverse trig functions. This is just the three main ones

  • Celestine Hale 2 years ago

    Thank you so much! You saved my life!

  • 1earflapping 2 years ago

    Can the theta also be in the right angle? If not, why not?

  • Julian Valencia 2 years ago

    thank you so much for this thorough explanation, you’ve helped a lot of people.. also I’m in love with you

  • Bill Lenker 2 years ago

    Thank you for the review. Haven’t seen much trigonometry since I retired as an optometry professor 12 years ago.
    Very good effort and easy to understand.

  • Joseph Bell 2 years ago

    Shame about the audio but great explanation

  • matar mbe 2 years ago

    you’ve got the scary smile of the beauty. you’ve got me trapped in your smile.

  • Banin Diar Sukmono 2 years ago

    High on potenuse 😂😂

  • Thomas Heaven 2 years ago

    Don’t wanna sound cliche or that im hitting on the woman but a beautiful teacher and math feel so counter productive mixed together. It’s so hard for me to even concentrate to begin with. 😂

  • Paul Bull 2 years ago

    45 years old and finally someone made sense of this for me. Thank you.

  • Dexin Lei 2 years ago

    I can’t focus on the content

  • Bronn Blackwater 2 years ago

    thanks!💖 and Hot!🔥

  • Bob Pederson 2 years ago

    She does not speak clearly.

  • CHELSEA KIRBY 2 years ago

    Ad: do the vidios from 2006 really help
    Me: Yes they do.

    • mansaurus saad 2 years ago

      That annoying maths pug one omds

  • CHELSEA KIRBY 2 years ago

    I know in grade 3 but i understand this

  • Judy Hopps 2 years ago

    I still don’t understand, but the first time ever, I understand the parts I don’t understand, and am going to watch it a second time so I understand them <3

  • Siya Pathak 2 years ago

    this is so useful thankyou!(:

  • Sweta Haldankar 2 years ago

    That was very useful.. Thnk u

  • hemanta khatri 2 years ago

    Wow i love the way you teach

  • J Chr G 2 years ago

    And after all the world has come to this were I come to the conclusion that helpfull people don’t get halve the reward as negative behaving people,
    So than why not behave at the same negative algorithm
    The only thing I need to do is put an angle on that thing so it drops to earth on a correct angle…haha
    Nuclear bombs should be landing at an angle on the earth to inflict most damage
    Instead of dropping it at a straight 90° angle on earth
    and 45° would cause the most dispersing of the nuclear poison in one direction
    To get it further figure out the wind direction and so it’s poison may flow with the wind to reach even greater distances

  • Michael 2 years ago

    This helped so much during this “online only” coursework I’m doing rn. Thank you 🙂

  • Anthony 22 2 years ago

    Aviles sent me here

  • Rajeesha Ammu 2 years ago


  • Zenika 2 years ago

    i find this video the day before my trig final 😭

  • aqabdulaziz 2 years ago

    Your expression on your face suggests that you hate teaching.

  • Ronald Martens 2 years ago

    My father was a builder and I’m a plasterer although take on building jobs. Recently I have been working on building pergolas. A client gave a plan to build a pergola which had angles so I drew plans to incorporate a pitch. The client kept changing his mind so all the drawings I did was a waste of time. I relied on my drawings to calculate pitch from rise and at a certain angle. Okay, I can work out the degree pitch and the length of material required for a certain degree angle.
    I want to know the formula so I can work it out for myself which brings me here.
    I’m a self learn person who has not learned about sin cos tan at school. I don’t understand tan apart from it is a value or a rise. Tan can be called anything so it’s the formula for every metre run divided by the base length or whatever. What got me struck is a small – figure under the tan to work out an equation which are scientific values I don’t understand. I sort of want to create my own formula to achieve the right results. I’m sure there will be many methods which in the end return same results. My drawing programme goes to .0001 mm although drawing angles only returns . 001 so it can be within less than 1/2 mm out when calculating different distances.
    I have spent time writing a spread sheet for angle pitches to 80 degrees starting at 1 metre square then calculating angles. I then have a reference which I call datum. Starting point. I then draw up other charts saw 1.2 metre or 5 metre. So I get the one metre datum and multiply be either 1.2 or 5 metre.
    Problem in building no one cares. There is not the level of accuracy I want to obtain in what I do. The pyramids is one such example that advanced civilisations existed and yet we are told slaves dragged stones and shapes with hand tools. That’s a joke right? Because the pyramids align true north and south also pointing to the constellation of Orion.
    The granite boxes have an accurate within 2/10,000 of an inch. So I guess trigonometry goes back 100,000 years old and longer.

  • Ronald Martens 2 years ago

    I’m just halfway. In the building we worked out the 3 4 5 formula to create a right angle 90degree. If you have a base 4 and height 3 the angle returns something like 36 degree and decimal. If you have a base 3 and height 4 its around 53 I also did opposite and it returned same values if taken from 180.
    I guess I’m taking on jobs outside my plastering so in carpentry it’s necessary to dissect angles also incorporating setting cornices on different architect designed roof pitches when setting plaster cornices.
    I told my daughter maths should be taught to incorporate the real world. Construction is one example where it can be practical.
    I was doing my leaving in high school it was around April and I changed subjects so had a few months to catch up on one subject. Two weeks later they ran a preliminary test on the new subject I took on. As I was behind the questions provided answers so it confused me I got 48%. So the school principle and another person stupid as they were called me up about my results and said we think you should leave school so I did. My subject was human biology and changed from geography which did nothing but charts.
    My daughter used to tease me and say we think you should leave school. I went on and did a few building units although qualified as a plasterer.

  • Eshan Gagguturi 2 years ago

    i am a 11 year old trying to understand this

  • Jhuma Banerjee 2 years ago

    a maths teacher to b so cute is hard to realize…………………… but its the truth unlike the other mathematical demons

  • social Engineer 2 years ago

    Who’s hungry for pizza? Still doesn’t show why I always get the smallest slice.

  • Ibrahim El Atabeh 2 years ago

    I making video 9k likes

  • Sarah Hernandez 2 years ago

    Not only are you beautiful but you have a great attitude with it. You really helped me, I was freaking out that I was going to have to watch 100000 videos to remember all this. Nope! Thanks to Nancy I am good! You are the best! Keep up this great content – xoxox

  • Kelle Velle 2 years ago

    She’s just like my teacher in algebra the face the body and also the way she speak and the reason why I learned algebra so fast😊

  • Chris Adrian 2 years ago

    I’m just shocked how she could write inverted

  • Soxruleyanksdrool 2 years ago

    I’m confused. She said theta is the angle that’s not the right angle. So in a right triangle, since there are two non-right angles, there are two thetas, correct? And if not, how do you know which of the two non-right angles is the theta?

  • jorge vazquez 2 years ago

    another way you can use to describe is Some Old Hippy Caught Another Hippy Trippin On Acid

  • Patrick C 2 years ago

    How do you draw a “wrong” triangle? Lol

    • cindia1977 2 years ago

      by not using your brains#

  • dibakar chakrabarty 2 years ago

    Thank you very much. Very simply you explained and you look so beautiful ….

  • Mark L. 2 years ago

    Trying to learn but your beauty is just tormentingly distractive

  • Alice Rose 2 years ago

    She’s left handed 😱💖

  • Rodolf 2 years ago

    She’s so pretty I can’t concentrate :4

  • ram bahdur 2 years ago

    she explain better than my school teachers

  • Lamar Visarraga 2 years ago

    She’s hot, but the way that she’s drawing those right angles is bugging me.

  • nappy 2 years ago

    She’s hot

  • Samar Singh 2 years ago

    Why does literally everyone say that “Thanks so much I found this video the night before my test!”- Like do they only study for the test ONE day before or what???

  • Samar Singh 2 years ago

    Left-handed people are smarter than right-handers.
    Am I right???

    (Edit)- Or is her writing hand reversed as well as the writing?

  • John Pereira 2 years ago

    I appreciate the great information. Thank you for this incredible video!!! 🙌🏼🙌🏼

  • HDś Caffè 2 years ago


  • Taher Ali 2 years ago

    Thanks a lot i like your way that you explain. 👍🏼🌹

  • Sameer Ashi 2 years ago

    Her handwriting is better than mine and she’s writing backwards

Comments are closed.