How is the volume of a torus calculated?

Answer 1

A cross section if a torus is a circle. If r is the radius of that circle and R is the distance from the center of the torus (hole) to the center of the circle noted above, the the volume of the torus (Using the Pappus Method) is

Volume = 2*pi*R*Area where Area is the area of the circle = pi*r² so

Volume = 2*pi*R*pi*r² = 2*pi²*R*r²