Question

Find the measure of the missing angle using the exterior angle sum theorm

Answer 1

r = 30°

Explanation:

According to the Exterior Angle Sum Theorem, the exterior angle, which is 90°, is equal to the 2 interior angles, which are 60° and r°. We know that the angle next to the exterior angle is 90°, and since all angle sums add up to 180°, r = 30°.