An interior angle of a regular polygon has a measure of 135°. What type of polygon is it?

A regular polygon’s interior angle and exterior angle add to 180°. So the exterior angle is 180° − 135° = 45°. Since the exterior angles total 360°, the polygon has 360° ÷ 45° = 8 sides, making it an octagon (choice B).

AI-written and checked against the verified answer.