Question

How would I find the diameter of a circle when area is given?

Answer 1

`d = 2sqrt(A/pi)`

Explanation:

The area `A` of a circle is given by `A = pi r^2` where `r` is the radius of the circle. But the radius is half the diameter, so if the diameter of the circle is `d`, we have

`A = pi(d/2)^2`

`=> A= pid^2/4`

`=>4/piA = d^2`

`=> sqrt(4/piA) = d`

Thus we have the diameter `d` as

`d = 2sqrt(A/pi)`