Question

question 9 of 10
what is the sum of the measures of the interior angles of an octagon?
a. 2160°
b. 1080°
c. 1440°
d. 360°
e. 2880°
f. 45°

Explanation:

Step1: Recall the formula

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

Step2: Identify the number of sides

An octagon has $n = 8$ sides.

Step3: Calculate the sum

Substitute $n = 8$ into the formula: $S=(8 - 2)\times180^{\circ}=6\times180^{\circ}=1080^{\circ}$.

Answer:

B. 1080°