Posted by **Sara** on Sunday, January 17, 2010 at 11:08am.

If given an a cos, sin, or tan of an angle of a right triangle, what steps would you take on your calculator to find the measure of that angle? (For example: cos A = .7986, find angle A, The opposite side is 3. The hypotnuse is 5. And the adjacent side is 4)

If someone would just explain what to do with a graphing calculator (TI-84), that would mean a lot! thanks

- geometry -
**drwls**, Sunday, January 17, 2010 at 11:20am
You write:

"For example: cos A = .7986, find angle A, The opposite side is 3. The hypotenuse is 5. And the adjacent side is 4"

but for a 3:4:5 triangle, the cosine is 0.8.

I don't have your calculator, but what you need is a cos^-1 or arc cosine key.

If cosA = 0.7986, A = cos^-1 0.7986 = 37.003 degrees.

## Answer This Question

## Related Questions

- Trig - Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < ...
- Math - 1. Write the expression as a function of an acute angle whose measure is ...
- math trigg. - which triangles do you use COS SIN or TAN?? You can use these ...
- MATH - 1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL ...
- Pre-calculus help - I have two problems I am stuck on, if you could show me how ...
- Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...
- Math sin/cos - On a piece of paper draw and label a right triangle using the ...
- Precalculus - I am trying to submit this homework in but i guess i'm not doing ...
- precalculus - For each of the following determine whether or not it is an ...
- Math - 1. Find the angle of smallest positive measure coterminal with an angle ...

More Related Questions