Question

Given a triangle with a = 12, A = 13°, and B = 12°, what is the length of c? Round to the nearest tenth.

Answer 1

22.54 units

Explanation:

Consider angles:

A = 13°, B = 12°, C = 180° - 13° - 12° = 155°

By Law of sines

a/SinA = b/SinB = c/SinC

in this case we are given a = 12, A = 13° and we found earlier that C = 155°

Hence

a/SinA = c/SinC

12/sin13° = c/sin155°

c = 12 (sin155° / sin13°)

c = 12 (1.8787)

c = 22.54 units