Triangular dipyramid
Type	Johnson
Faces	6 triangles
Edges	9
Vertices	5
Vertex configuration	-
Symmetry group	-
Dual polyhedron	-
Properties	convex

In geometry, the triangular dipyramid is a polyhedron made entirely out of 6 faces, which are all equilateral triangles, 9 edges, and 5 vertexes. It is a convex deltahedron. It is one of the Johnson solids (J₁₂). Although all faces are congruent and the solid is face-uniform, it is not a Platonic solid because some vertexes have three triangles at a point and others have four.

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

External links

• Johnson Solid -- from MathWorld (http://mathworld.wolfram.com/JohnsonSolid.html)