Answer:
∠A = 41
∠B = 82
∠C = 57
Explanation:
Sum of all the angles of triangle = 180
x + 10 + 2x -5 + 2x + 20 = 180
x +2x +2x + 10 - 5 +20 = 180 {Combine like terms}
5x + 25 = 180
5x = 180 - 25
5x =155
x = 155/5
x = 31
∠A = x + 10 = 31 + 10 = 41
∠B = 2x +20 = 2*31 + 20 = 62 + 20 = 82
∠C = 2x - 5 = 2*31 - 5 = 62 - 5 = 57