**Solution:**

Let ABC be a cone. A frustum DECB is cut by a plane parallel to its base.

Let *r*_{1} and *r*_{2} be the radii of the ends of the frustum of the cone and *h* be the height of the frustum of the cone.

In ΔABG and ΔADF, DF||BG

∴ ΔABG ∼ ΔADF

Volume of frustum of cone = Volume of cone ABC − Volume of cone ADE