Question

How do I solve this problem ​

Answer 1

C = 84 degrees

A = 2B
C = A + 20
A + B + C = 180

A = 2B
A/2 = B

A + (A/2) + (A+20) = 180
multiply each side by 2
2A + A + 2A + 40 = 360
combine like terms
5A + 40 = 360
subtract 40 from both sides
5A = 320
divide both sides by 5
A = 64

C = A + 20
C = 64 + 20
C = 84