If the area of an equilateral triangle is $36\sqrt{3}c{m}^2$, find its perimeter.

Let each side of an equilateral triangle be "a" cm
Area of an equilateral triangle $=36\sqrt{3}c{m}^2$ (Given)
Area of an equilateral triangle $=\frac{\sqrt{3}}{4}(side{)}^2$
$\Rightarrow 36\sqrt{3}=\frac{\sqrt{3}}{4}\times a^2$
$\Rightarrow a^2=144$
or $a=12cm$
Perimeter $=3(side)=3\times 12=36cm.$