In Triangle ABC, the measure of angle A is half the measure of angle B, which is 40 degrees more twice the measure of angle C. Find the measures of the three angle of this triangle.

Question

Can someone explain how to get the equation needed to solve the problem? Thanks in advance.

Answer 1

A=B/2,

B=2A

B=40+2C,

2C=B-40

C = (B-40)/2= B/2 -20 = A-20

A+B+C = 180

A + 2A + A-20 = 180

4A = 200

A = 50 degrees

B = 100 degrees

C = 30 degrees