Sphere Wikipedia
A sphere (from Ancient Greek σφαῖρα (sphaîra) 'globe, ball') is a geometrical object that is a threedimensional analogue to a twodimensional, a sphere is the set of points that are all at the same distance r from a given point in threedimensional space. That given point is the centre of the sphere, and r is the sphere's radius. The earliest known mentions of spheres ...