Question

If the measure of angle $c$ is double the measure of angle $b$, what is the measure of angle $a$ in triangle $abc$?

Answer 1

According to what you have given us, the only way we can express angle A is in terms of b. C= 2b and according to the triangle angle-sum theorem, a + b + 2b + 180. Solve this for a to get a = 180-3b. Can't do much more than that with what I have.

Answer 2

117

Explanation:

21(2) = 42

180-(42+21)=117

That's ur answer. R u doing this for AoPS?