Polyhedron Models
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A polyhedron (one polyhedron, many polyhedra, or polyhedrons) is a geometrical shape. It has flat faces, and straight edges. Usually it is defined by the number of faces, or edges.
Usually, polyhedra are named by the number of faces they have. The first polyhedra are the tetrahedron, which is made of four triangles, pentahedron (five faces, can look like a four-sided pyramid), hexahedron (six faces, a cube if it is regular), and heptahedron (seven faces, can look like a prism based on a pentagon, or a pyramid based on a hexagon amongst others).
http://simple.wikipedia.org/wiki/Polyhedron
Usually, polyhedra are named by the number of faces they have. The first polyhedra are the tetrahedron, which is made of four triangles, pentahedron (five faces, can look like a four-sided pyramid), hexahedron (six faces, a cube if it is regular), and heptahedron (seven faces, can look like a prism based on a pentagon, or a pyramid based on a hexagon amongst others).
http://simple.wikipedia.org/wiki/Polyhedron