3. Find the volume of a pyramid whose base is a square with sides of length L and whose height is h.

4. Find the volume of a torus with radii r and R.

9. Find the volume of the solid whose base is a disk of radius r and whose cross-sections are equilateral triangles.

16. Find the volume of a pyramid whose base is a square with sides of length L and whose height is h.

17. Find the volume of a torus with radii r and R.

18. Find the volume of the solid whose base is a disk of radius r and whose cross-sections are equilateral triangles.