Sphere is a solid figure bounded by a spherical surface or sphere, formed by rotating a circle about its diameter. The sphere is a rotating surface.
The distance from any point on the surface of the sphere to its center is called the radius of the sphere.
The diameter of a sphere is a straight line connecting any two points on the surface or sphere and passing through the center of the sphere. All diameters of a sphere are of equal length. The diameter is twice the radius.
$$S=4 \pi r^{2}=\pi d^{2}$$
where,
π— Pi or Archimedean constant is a mathematical constant that is the ratio of the circumference of a circle to its diameter; the approximate value of pi is 3.14159265359;
r— radius of the sphere;
d— diameter of the sphere.
The volume of a sphere is equal to one-third of the product of the sphere's surface area and its radius:
$$V=\frac{1}{3}\times S \times r=\frac{4}{3}\pi r^{3}$$
The surface area of a sphere is calculated as four times pi times the square of the radius.
The volume of a sphere is calculated as four thirds pi times the cube of the radius.
The diameter is twice the radius and passes through the center of the sphere from one side to the other.