### Home > GC > Chapter 12 > Lesson 12.2.3 > Problem 12-80

12-80.

If the sum of the interior angles of a regular polygon is 2160°, how many sides must it have? Homework Help ✎

According to the formula for the sum of the interior angles of an *n*-gon, 180°(*n* - 2) = 2160°.

The polygon has 14 sides.