Question

Express the area of a circle, a, as a function of its circumference,
c.

Answer 1

Area = PI * radius^2

Circumference = 2 * PI * radius
radius = Circumference / 2 * PI

So, Area = PI * (Circumference / 2 *PI) * (Circumference / 2 *PI)
So, Area = Circumference^2 / (4*PI)