WAEC 2022 · Paper 1 · Q20

An exterior angle of a regular polygon is $22.5^\circ$ . Find the number of sides.

Worked solution (try it first)

The exterior angles of a regular polygon are equal and add up to $360^\circ$ , so the number of sides is $360 \div 22.5$ .
Double both numbers to clear the decimal: $720 \div 45 = 16$ , option D.