Question

Regular pentagon ABCDE and regular hexagon AEFGHI are drawn on opposite sides of line segment AE such that they are coplanar. What is the degree measure of exterior angle DEF?

Answer 1

72 degrees!

Explanation:
An interior angle for a regular hexagon is 120 degrees and an interior angle of a pentagon is 108 degrees. Add these values together to equal the interior angle DEF. so:

180 + 108 = 288

then, subtract this value from 360 degrees to get the exterior angle:

360 - 288 = 72

therefore the exterior angle DEF = 72 degrees