Question

Find the measure of interior angle of a regular octagon.

• A. ${135}^{\circ }$
• B. ${105}^{\circ }$
• C. ${145}^{\circ }$
• D. ${120}^{\circ }$

Answer 1

The correct option is A

${135}^{\circ }$

The sum of exterior angles of a regular octagon $={360}^{\circ }$
$\therefore$ Each exterior angle of a regular octagon $=\frac{{360}^{\circ }}{8}={45}^{\circ }$

Each interior angle of a regular octagon $={180}^{\circ }-{45}^{\circ }={135}^{\circ }$