# What is the measure of an interior angle of a 21-gon? (Round to the nearest Hundreth)?

Apr 19, 2018

162.86

#### Explanation:

On a regular polygon the exterior angle is found by dividing 360 by the number of sides. Then subtract this answer from 180 to find the interior angle.

$\frac{360}{21} = \frac{120}{7} = 17 \frac{1}{7}$

180-17$\frac{1}{7}$=162$\frac{6}{7}$

=162.857142