A three dimensional solid formed by revolving, not rotating a disc about a line. In the Cartesian Plane, if the disc is revolved about the y-axis, its shape (the cross-section of the toroid) is given by the equation `(x-b)`^{2} + y^{2} = a^{2}. (i.e. a circle, with radius a, centered at the point `(b,0)`) The volume of this toroid is then given by `V = 2Pi`^{2}a^{2}b.