### Home > INT2 > Chapter 12 > Lesson 12.2.2 > Problem12-80

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.