Question

1. what is the sum of the interior angle measures of an octagon?

a. 1,080°
b. 1,440°
c. 1,620°
d. 360°

Explanation:

Step1: Recall the formula for the sum of interior angles of a polygon

The formula for the sum of the interior angle measures of a polygon with \( n \) sides is \( S=(n - 2)\times180^{\circ} \).

Step2: Determine the number of sides of an octagon

An octagon has \( n = 8 \) sides.

Step3: Substitute \( n = 8 \) into the formula

\[

$$\begin{align*} S&=(8 - 2)\times180^{\circ}\\ &=6\times180^{\circ}\\ & = 1080^{\circ} \end{align*}$$

\]

Answer:

A. \( 1,080^{\circ} \)