# Elongated pentagonal bipyramid

Appearance

Elongated pentagonal bipyramid | |
---|---|

Type | JohnsonJ_{15} – – J_{16}J_{17} |

Faces | 10 triangles 5 squares |

Edges | 25 |

Vertices | 12 |

Vertex configuration | 10(3^{2}.4^{2})2(3 ^{5}) |

Symmetry group | D_{5h}, [5,2], (*522) |

Rotation group | D_{5}, [5,2]^{+}, (522) |

Dual polyhedron | Pentagonal bifrustum |

Properties | convex |

Net | |

In geometry, the **elongated pentagonal bipyramid** or **pentakis pentagonal prism** is one of the Johnson solids (*J*_{16}). As the name suggests, it can be constructed by elongating a pentagonal bipyramid (*J*_{13}) by inserting a pentagonal prism between its congruent halves.

A Johnson solid is one of 92 strictly convex polyhedra that is composed of regular polygon faces but are not uniform polyhedra (that is, they are not Platonic solids, Archimedean solids, prisms, or antiprisms). They were named by Norman Johnson, who first listed these polyhedra in 1966.^{[1]}

## Dual polyhedron[edit]

The dual of the elongated square bipyramid is a pentagonal bifrustum.

## See also[edit]

## External links[edit]

**^**Johnson, Norman W. (1966), "Convex polyhedra with regular faces",*Canadian Journal of Mathematics*,**18**: 169–200, doi:10.4153/cjm-1966-021-8, MR 0185507, Zbl 0132.14603.