I don't know if this should be in Geometry or in Calculus since I've since quite a lot of derivations using calculus.

I've always wondered how the Vol. of the Sphere = (4/3)(pi)(r^3) [I'm sorry I put 4(pi)(r^2)]

So can I use steradians to prove it?

So here's my way:

The volume of a cone (I'm thinking that a steradian is a cone with a curved base) = 1/3(Are of the Base)(height)

And there are 4 steradians in a sphere so

4[(1/3)(2)(pi)(r^2)(h)]

=(4/3)(pi)(r^2)(r) since the vertex of a steradian is at the center of the circle

=(4/3)(pi)(r^3)

Is this correct?