3.9. A sphere of radius $R$ touches one base of a truncated cone and touches its lateral surface along a circumference, which is the circumference of the other base of the cone. Find the volume of the body consisting of the cone and the sphere, if the area of the complete surface of this body is $S$.

A sphere of radius $R$ touches one base of a truncated cone and touches its lateral surface along a circumference, which is the circumference of the other base of the cone. Find the volume of the body consisting of the cone and the sphere, if the area of the complete surface of this body is $S$.
3.9. The same considerations as in problem 3.8 show that the volume of this body is $S R / 3$.