Question

Find the value of each interior angle of a regular decagon.

• A. 60${}^{\circ }$
• B. 144${}^{\circ }$
• C. 90${}^{\circ }$
• D. 1440${}^{\circ }$

Answer 1

The correct option is B

144${}^{\circ }$

A regular polygon is a polygon in which all the sides and angles are equal.

A decagon is a polygon having 10 sides.

Exterior angle (e°) = $\frac{360°}{10}$

Exterior angle (e°) = 36°

We know, Interior angle (i°) + Exterior angle (e°) = 180°

Interior angle (i°) + 36 = 180°

Interior angle (i°) = 144°