Elongated bipyramid
| Elongated bipyramid | |
|---|---|
Example: elongated hexagonal bipyramid  | |
| Faces | 2n triangles n squares  | 
| Edges | 5n | 
| Vertices | 2n + 2 | 
| Symmetry group | Dnh, [n,2], (*n22) | 
| Rotation group | Dn, [n,2]+, (n22) | 
| Dual polyhedron | bifrustums | 
| Properties | convex | 
In geometry, the elongated bipyramids are an infinite set of polyhedra, constructed by elongating an n-gonal bipyramid (by inserting an n-gonal prism between its congruent halves).
There are three elongated bipyramids that are Johnson solids:
- Elongated triangular bipyramid (J14),
 - Elongated square bipyramid (J15), and
 - Elongated pentagonal bipyramid (J16).
 
Higher forms can be constructed with isosceles triangles.