Chapter 12, Problem 10CT

To determine

To find: The measure of an interior angle of a regular $9\text{-gon}$ .

Answer to Problem 10CT

The value of an exterior angle of a regular $9\text{-gon}$ is ${40}^{\circ }$ .

Explanation of Solution

Given information: A regular $9\text{-gon}$ .

Calculation: A regular $9\text{-gon}$ is a nine-sided polygon.

Sum of the exterior angles of a regular $9\text{-gon}$ is ${360}^{\circ }$ .

Let’s find an exterior of the regular $9\text{-gon}$ ,

  $\begin{array}{l}=\frac{{360}^{\circ }}{9}\\ ={40}^{\circ }\end{array}$

Hence, The value of an exterior angle of a regular $9\text{-gon}$ is ${40}^{\circ }$ .