Question

Помогите, пожалуйста, 25 балов​

Answer 1

// ∠C = 90

∠A + ∠B = 90

∠A = 90 - ∠B

(180 - ∠A) - (180 - ∠B) = 20

180 - (90 - ∠B) - 180 + ∠B = 20

-90 + ∠B + ∠B = 20

-90 + 2∠B = 20

2∠B = 20 + 90

2∠B = 110

∠B = 55

∠A = 90 - 55 = 35