The truncated triangular prism is an undecagon obtained by truncation of a triangular prism. It has 18 vertices, 27 edges, and 11 faces. As a canonical polyhedron with unit midradius, its edges are of three different lengths,
 |  |  | (1) |
 |  |  | (2) |
 |  |  | (3) |
with tallies of 12, 12, and 3 respectively.
The canonical truncated triangular prism has surface area and volume given by
 |  |  | (4) |
 |  |  | (5) |
Its net is illustrated above.
The truncated triangular prism is also the polyhedron dual of the Goldner-Harary polyhedron, as illustrated above for the canonical versions of these solids.
