Learn Basic Trigonometry Formulas for Right Triangles | Physics Class Help

  • Thread starter Thread starter Revolver
  • Start date Start date
  • Tags Tags
    Formulas
AI Thread Summary
Basic trigonometry formulas for right triangles include sine (sin), cosine (cos), and tangent (tan), defined as sin = opposite/hypotenuse, cos = adjacent/hypotenuse, and tan = opposite/adjacent. For a right triangle with a hypotenuse of 7 and an angle of 35 degrees, users can apply these formulas to find the lengths of the sides. The discussion emphasizes the importance of identifying opposite and adjacent sides based on the given angle. Various mnemonic devices like SOHCAHTOA are shared to aid in memorization. Understanding these concepts is essential for solving problems in physics involving right triangles.
Revolver
Messages
14
Reaction score
0
I haven't had precalc 2 yet, so I'm not too familiar with sin, cos, tan, but I need this for my physics class.

So if you guys don't mind giving me the formulas of sin, cos, and tan.. for example: Sin angle A = width/length etc. If I have a right triangle with a hypotonuse of 7, and an angle of 35 degrees, what is the angle, and the other side.
 
Physics news on Phys.org
A lot of people like this little device:

SOHCAHTOA
Sin = Opposite/Hypotenuse SOH
Cos = Adjacent/Hypotenuse CAH
Tan = Opposite/Adjacent TOA
 
SOHCAHTOA...

sin = opposite/hypotenus

cos = adjacent/hypotenus

tan = opposite/adjacent

You should be able to figure it out from here...
 
OK MathIsHard... we were typing at the same time and your spelling is better than mine...
 
oops, sorry, Doc! :redface:
 
Well here's a question.. how do you know which is the opposite and which is the adjacent? Let's say you are given a triangle with sides of 4, 5 and 6, and you are required to find the angles.. how do you know which method to use?
 
I was taught that it was 'CHIEF' SOHCAHTOA !
 
  • #10
I was taught reading down the columns

Oscar Sally
Has

A Can
Hairy

Old Tell
A$$

Trig functions work on Right triangles. H is the hypotenuse, that is the side opposite the right angle. The other 2 angles have an Adjacent side and an Opposite side. That is the opposite and Adjacent in the trig definitions.
 
  • #11
(i know this thread is a little dated, but still nice for reference :smile:)
I was taught "Some Old Horse Came A Hoppin' Through Our Alley" ,
using the first letters of each word will give you this

sin = Some Old Horse (sin = opposite/hypotenuse)
cos = Came A Hoppin' (cos = adjacent/hypotenuse)
tan = Through Our Alley (tan = opposite/adjacent)
 
Last edited by a moderator:
Back
Top