A Polyhedron with one face a Polygon and all the other faces Triangles with a common
Vertex. An -gonal regular pyramid (denoted ) has Equilateral
Triangles, and is possible only for , 4, 5. These correspond to the Tetrahedron,
Square Pyramid, and Pentagonal Pyramid, respectively. A pyramid therefore has a single cross-sectional shape in
which the length scale of the Cross-Section scales linearly with height. The Area at a height is given by

(1) |

(2) |

The Centroid is the same as for the Cone, given by

(3) |

(4) |

**References**

Beyer, W. H. (Ed.) *CRC Standard Mathematical Tables, 28th ed.* Boca Raton, FL: CRC Press, p. 128, 1987.

Hart, G. W. ``Pyramids, Dipyramids, and Trapezohedra.'' http://www.li.net/~george/virtual-polyhedra/pyramids-info.html.

© 1996-9

1999-05-26