Question

Find the measure of angle A

Answer 1

45°

Explanation:

The sum of interior angles in a triangle is equal to 180°

60 + x + 87 + x + 57 = 180 add like terms

2x + 204 = 180 subtract 204 from both sides

2x = -24 divide both sides by 2

x = -12

angle A is x + 57 so if we replace A with the value we found

(-12) + 57 = 45°