Question

If a copper wire is bend to make a square whose area is $324{cm}^2$. If the same wire is bent to form a semicircle, then find the radius of semicircle.

Answer 1

Area of square $=324c{m}^2$
$a^2=324$
$a=\sqrt{324}=18$

So, Side of square $a=18cm$

Length of wire =perimeter of square $=18\times 4$ = $72cm$

Let radius of semicircle be $r$

Then According to question $,\pi \times r=72cm$

Solving we get $,r=\frac{252}{11}cm$