The measure of each interior angle of a regular octagon is:

Correct option is C

​Given:

A regular octagon has n = 8 sides

Formula Used:

Sum of interior angles of a polygon = (n−2) × 180

$$\text{Each interior angle} = \frac{\text{Sum of interior angles}}{n}$$ 

Solution:

Sum of interior angles = (8 − 2) × 180$$^\circ$$​ = 6 × 180$$^\circ$$​ = 1080$$^\circ$$

Measure of each interior angle:

​$$\text{Each interior angle} = \frac{1080^\circ}{8} = 135^\circ$$​