Find angle B in triangle ABC if angle C = 90 degrees, angle A – angle B = 20 degrees.

The sum of all angles in any triangle is 180 °. It is known that the angle С is equal to 90 °, so the sum of the other angles is equal to:
A + B = 180 ° – 90 ° = 90 °.
It is known that the angle B is 20 ° less than the angle A, we express it in terms of x and solve the problem using the equation:
х ° – angle В;
Then:
(x + 20 °) – angle A.
Let’s compose and solve the equation:
x + (x + 20) = 90;
x + x + 20 = 90;
2x + 20 = 90;
2x = 90 – 20;
2x = 70;
x = 70/2;
x = 35 ° – angle B;
(x + 20) = 35 + 20 = 55 ° – angle A.
Answer: 35 °