An undecahedron is a polyhedron having 11 faces. Examples include those illustrated above and summarized in the following table.
 |  |  | name |
| 11 | 8 | 17 | biaugmented
triangular prism ( ) |
| 11 | 11 | 20 | elongated pentagonal pyramid
( ) |
| 11 | 11 | 20 | decagonal pyramid |
| 11 | 13 | 22 | augmented hexagonal prism
( ) |
| 11 | 18 | 27 | truncated triangular prism |
| 11 | 18 | 27 | nonagonal prism |
