Answer:
∠A = 100
∠B = 50
∠C = 30
Step-by-step explanation:
Sum of all angles of triangle = 180
∠A + ∠B + ∠C = 180
2x +x + x - 20 = 180 {Combine like terms}
4x - 20 = 180
Add 20 to both sides
4x = 180 + 20
4x = 200
Divide both sides by 4
x = 200/4
x = 50
∠A = 2x = 2*50 = 100
∠B = x = 50
∠C = x - 20 = 50 - 20 = 30
