Answer:
45 degrees
Explanation:
Using the pythagorean theorem, the 3rd side=19. So the triangle is isosceles and therefore the 2 angles we don't know the measure of are congruent. One angle measures 90 degrees. So the last 2 angles must be 90 together, since we know a triangle equals 180 degrees. Therefore the angle we are trying to find is 45 degrees.