# Three Dimentional Geometry

## 3-d geometry

is the geometry of three-dimensional space,

the kind of space we live in

Polyhedron

A solid with flat faces (from Greek poly- meaning "many" and -edron meaning "face")

Non-polyhedra

A solid with curved side or a mix of curved and flat sides.

Prism

**a solid geometric figure whose two end faces are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms.**

Pyramid

a monumental structure with a square or triangular base and sloping sides that meet in a point at the top, esp. one built of stone as a royal tomb in ancient Egypt.

http://www.mathwords.com/p/pyramid.htm

Cone a solid or hollow object that tapers from a circular or roughly circular base to a point.

Cylinder a solid geometric figure with straight parallel sides and a circular or oval section.

Sphere a round solid figure, or its surface, with every point on its surface equidistant from its center.

Torus a surface or solid formed by rotating a closed curve, esp. a circle, around a line that lies in the same plane but does not intersect it (e.g., like a ring-shaped doughnut).

Net flat shape opened up