Suppose that the radius X of a circle is a random variable having the following p.d.f.:

f(x)={ (1/8)(3x=1) for 0<x<2

0 otherwise

Determine the p.d.f. of the area of the circle and the circumference of the circle.

can anyone help me with this one? do i just plug f(x) into the equations for area and circumference? how does that apply to the pdf of area and circumference???