A tetradecahedron is a
polyhedron with 14
faces. There are numerous topologically distinct forms of a tetradecahedron, with many constructible entirely with
regular polygon faces.
A tetradecahedron is sometimes called a tetrakaidecahedron.[1][2] No difference in meaning is ascribed.[3][4] The Greek word kai means 'and'. There is evidence that mammalian
epidermal cells are shaped like flattened tetrakaidecahedra, an idea first suggested by
Lord Kelvin.[5] The polyhedron can also be found in soap bubbles and in
sintered ceramics, due to its ability to
tesselate in 3D space.[6][7]
Convex
There are 1,496,225,352 topologically distinct convex tetradecahedra, excluding mirror images, having at least 9 vertices.[8] (Two polyhedra are "topologically distinct" if they have intrinsically different arrangements of faces and vertices, such that it is impossible to distort one into the other simply by changing the lengths of edges or the angles between edges or faces.)
Examples
An incomplete list of forms includes:
Tetradecahedra having all
regular polygonal faces (all exist in irregular-faced forms as well):
The
British £1 coin in circulation from 2017 – with twelve edges and two faces – is an irregular dodecagonal prism, when one disregards the edging and relief features.[9]