WAEC 2023 · Paper 1 · Q26

The interior angle of a regular polygon is 6 times its exterior angle. Find the number of sides of the polygon.

Worked solution (try it first)

Let the exterior angle be $e$ .
The interior angle is $6e$ , and the two add up to $180^\circ$ : $7e = 180^\circ$ .
So $e = \frac{180^\circ}{7}$ .
The number of sides is $360 \div \frac{180}{7} = 360 \times \frac{7}{180}$
$= 14$ , option B.