Question

Why must angle A be 135°

Answer 1

Because a is the measure of the interior angle of a regular octagon.

Explanation:

Given figure is of a regular octagon.

Measure of one interior angle of regular octagon is given as:

`a = ((n - 2) * 180 \degree)/(n) \\ \\ = ((8 - 2) * 180 \degree)/(8) \\ \\ = (6 *180 \degree )/(8) \\ \\ = (1080 \degree)/(8) \\ \\ \huge \red{ \boxed{a= 135 \degree}}`