JAMB 2004 · UME · Q25

$PQRSTV$ is a regular polygon of side 7 cm inscribed in a circle. Find the circumference of the circle $PQRSTV$ . $\left[\pi = \frac{22}{7}\right]$

Worked solution (try it first)

$PQRSTV$ has six sides, so it is a regular hexagon.
Joining the centre to each vertex makes six equilateral triangles, so the radius equals the side: $r = 7$ cm.
Circumference $= 2\pi r = 2 \times \frac{22}{7} \times 7$ .
So the circumference is 44 cm, option C.