in triangle ABC,!!!!!!!!!!!!!!!!!!!!!!

Question

angle b is twice as large as angle A. Angle C is 20 degree less than angle B. Find the 3 angles

Answer 1

In triangle ABC, ∠A + ∠B + ∠C = 180

Let ∠A be A

Given that  B = 2A and C = B - 20

                                   => C = 2A - 20

Therefore A + 2A + 2A - 20 = 180

                  5A - 20 + 20 = 180 + 20

                 5A = 200

                 A = 200 / 5

                 A = 40

B = 2A = 2 * 40 = 80

C = B - 20 = 80 - 20 = 60

Therefore angles A, B, C are 40, 80 and 60 respetively.