Question

what is the measure of each interior angle of a regular octagon? 45° 60° 120° 135°

Explanation:

Step1: Recall the formula for interior angle

The formula for the measure of each interior angle $\theta$ of a regular $n$-sided polygon is $\theta=\frac{(n - 2)\times180^{\circ}}{n}$.

Step2: Identify the number of sides of an octagon

An octagon has $n = 8$ sides.

Step3: Substitute $n = 8$ into the formula

$\theta=\frac{(8 - 2)\times180^{\circ}}{8}=\frac{6\times180^{\circ}}{8}=135^{\circ}$.

Answer:

$135^{\circ}$