Question

A rectangle with length =$18cm$ and breadth =$12cm$ has same perimeter as that of a regular pentagon. Find the side (in $cm$) of the pentagon.

Answer 1

Given that,

Perimeter of rectangle = Perimeter of regular pentagon

$⟹2(l+b)=5a$

$⟹2(18+12)=5a$

$⟹60=5a$

$⟹a=\frac{60}{5}$

$\therefore a=12cm$

i.e., Side of regular pentagon $=12cm$