If you are willing to accept that the volume of a cone is ⅓ Bh where B is the area of the base and if you are willing to accept that the area of the surface of the sphere is 4 pi r^2 then you can get the volume of the sphere by adding an infinite number of thin cones radiating from the center with height = r. The sum of the B values is the area of the surface of the sphere giving ⅓ r * 4 pi r^2 = 4/3 pi r^3.