The Triangular Bipyramid

The triangular bipyramid is the 12th Johnson solid (J12). It has 5 vertices, 9 edges, and 6 faces (6 equilateral triangles).

The triangular bipyramid

The triangular bipyramid can be constructed by attaching two tetrahedra to each other.

If a triangular prism is inserted between the two constituent tetrahedra, an elongated triangular bipyramid (J14) is produced.

The triangular pyramid (J12) is the dual of a non-uniform triangular prism, one with rectangular faces with edge ratio √6 : 1 rather than squares. The dual of the uniform triangular prism is a different triangular pyramid—one with isosceles triangles (with edge ratio 2 : 3) rather than equilateral triangles.


Here are some views of the triangular bipyramid from various angles:

Projection Envelope Description

Top view.


Side view.


Front view.


The Cartesian coordinates of the triangular bipyramid with edge length 2 are:

Last updated 10 Jan 2023.

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