Question

The measure of each interior angle of a regular octagon is

• A. ${140}^{\circ }$
• B. ${135}^{\circ }$
• C. ${210}^{\circ }$

Answer 1

Answer: (A), (B)

${135}^{\circ }$

The given polygon is a regular octagon.
$\therefore n=8$.

Sum of exterior angles $={360}^{\circ }$

Measure of each interior angle $=\frac{{360}^{\circ }}{8}={45}^{\circ }$

Interior and exterior angles of a polygon form a linear pair.

Measure of each interior angle $={180}^{\circ }-{45}^{\circ }={135}^{\circ }$