The volume of a cone is:

V=(TT x r squared x height) / 3

So:

R squared = (3 x volume) / TT x h

r= square root of (3 x volume) / (TT x h)

V=(TT x r squared x height) / 3

So:

R squared = (3 x volume) / TT x h

r= square root of (3 x volume) / (TT x h)