Question

1. find the measure of z. regular octagon 135° 120° 144°

Explanation:

Step1: Recall polygon - angle formula

The sum of interior - angles of a polygon is given by $S=(n - 2)\times180^{\circ}$, where $n$ is the number of sides of the polygon. For an octagon, $n = 8$.

Step2: Calculate the sum of interior - angles

$S=(8 - 2)\times180^{\circ}=6\times180^{\circ}=1080^{\circ}$.

Step3: Find the measure of each interior angle of a regular octagon

Since a regular octagon has all interior angles equal, each interior angle $z=\frac{(8 - 2)\times180^{\circ}}{8}=\frac{1080^{\circ}}{8}=135^{\circ}$.

Answer:

$135^{\circ}$