Formula: Circle Area Radius
$$A ~=~ \pi \, r^2$$
$$A ~=~ \pi \, r^2$$
$$r ~=~ \sqrt{ \frac{A}{\pi} }$$
Area
$$ A $$ Unit $$ \mathrm{m}^2 $$
Area of a circle with radius \(r\).
Radius
$$ r $$ Unit $$ \mathrm{m} $$
Radius of the circle. The diameter \(d\) of the circle is \( d = 2r\).
Pi
$$ \pi $$ Unit $$ - $$
Pi is a mathematical constant and has the value \( \pi ~=~ 3.1415926... \)