Spherical Segment of Two Bases

a part of a sphere bounded by two parallel planes intersecting the sphere (see Figure 1). The volume of such a solid is V = πh(3a² + 3b2 + h²)/6,

Figure 1

and the area of the solid’s curved surface, which is called a zone, is S = 2πRh; here, R is the radius of the sphere, h is the distance between the planes of the bases, and a and b are the radii of the bases.