A **spherical surface** is the locus of the points of space that are equidistant from a fixed point (center of the sphere)
and a **sphere** is the space bounded by spherical surface.

The **area** of spherical surface is as four time the area of a maximum circle (circle that has been from to cut a sphere whit a plane that is in the center of this sphere):

The **volume** of a sphere is equal to: