Geometric 3D Objects Box and Sphere

THREE-DIMENSIONAL PRIMITIVES
In a three-dimensional world, we can have a far greater variety of geometric objects than we can in two dimensions. When we worked in a two-dimensional plane in Chapter 2, we considered objects that were simple curves, such as line segments, and flat objects with well-defined interiors, such as simple polygons. In three dimensions, we retain these objects, but they are no longer restricted to lie in the same plane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .