Science Fair Project Encyclopedia
Pentagonal dipyramid
In geometry, the pentagonal dipyramid is one of the Johnson solids (J13). It is a three-dimensional solid that has equilateral triangles only as faces. It is a deltahedron. It is not a Platonic solid because some vertexes have four faces meeting and others have five faces. However, the solid is face-uniform: for any two faces A and B, there is a rotation of the solid that places face A over face B while leaving the solid occupying the same volume.
The 92 Johnson solids were named and described by Norman Johnson in 1966.
External links
03-10-2013 05:06:04
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details