(Translated by https://www.hiragana.jp/)
Square pyramid - Wikipedia Jump to content

Square pyramid

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by AndrewKepert (talk | contribs) at 10:37, 1 August 2005 (rv junk). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Square pyramid
TypeJohnson
J92 - J1 - J2
Faces4 triangles
1 square
Edges8
Vertices5
Vertex configuration4 of 32.4
1 of 34
Symmetry groupC4v
Dual polyhedronself
Propertiesconvex

In geometry, the square pyramid, a pyramid with a square base and equilateral sides, is one of the Johnson solids (J1).

The 92 Johnson solids were named and described by Norman Johnson in 1966.

It is worth noting that the Johnson solid "square pyramid" is specifically the one square pyramid whose triangular sides are all equilateral triangles. Other square pyramids, such as the Great Pyramid of Giza, are not similar to the Johnson solid; the pyramid at Giza, for example, has isosceles sides of base 756 feet and slant height 719 feet. (That pyramid has the interesting property that the area of each triangular face is equal to the square of its height.)

External link