Question

If the perimeter & area of a circle are numerically equal, then find the radius of the circle.

Answer 1

As we know that,

Perimeter of circle $=2\pi r$

Area of circle $=\pi r^2$

Given that the perimeter and area of circle are numerically equal.

Therefore,

$\pi r^2=2\pi r$

$r^2-2r=0$

$r(r-2)$

$\Rightarrow r=0$ or $r=2$