Question

Calculate the value of the exterior angle

Answer 1

An exterior angle of the triangle equals to the sum opposite interior angles, so

8x+15 = (4x+5) + (3x+20)

8x +15 = 7x +25

x=10

Now, we can calculate the exterior angle.

8x+15 = 8*10 + 15 = 80+15 = 95

Answer is 95⁰.