Elongated pentagonal rotunda
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| Elongated pentagonal rotunda | |
|---|---|
 |
|
| Type | Johnson J20 - J21 - J22 |
| Faces | 2.5 triangles 2.5 squares 1+5 pentagons 1 decagon |
| Edges | 55 |
| Vertices | 30 |
| Vertex configuration | 10(42.10) 10(3.42.5) 2.5(3.5.3.5) |
| Symmetry group | C5v |
| Dual | - |
| Properties | convex |
In geometry, the elongated pentagonal rotunda is one of the Johnson solids (J21). As the name suggests, it can be constructed by elongating a pentagonal rotunda (J6) by attaching a decagonal prism to its base. It can also be seen as an elongated pentagonal orthobirotunda (J42) with one pentagonal rotunda removed.
The 92 Johnson solids were named and described by Norman Johnson in 1966.
