In triangle RST, RT = 9, ST = 15, and angle R = 120 degrees. To the nearest tenth, what is angle S?

Guest Mar 26, 2021

#1**+1 **

You can solve the question using the law of sines:

(sin A)/a = (sin B)/b = (sin C)/c

A, B and C are angles in the triangle; a, b, and c are the side lengths opposite to their respective angles.

Plugging this in we get:

sin(120)/15 = sin(S)/9

sin(120) = sin(S) * 5/3

sin^{-1}{[sin(120)]/(5/3)} = S

**S ≈ 31.3°**

Solved! :)

ArithmeticBrains1234 Mar 26, 2021