Hendecagrammic prism
In geometry, a hendecagrammic prism is a star polyhedron made from two identical regular hendecagrams connected by squares. The related hendecagrammic antiprisms are made from two identical regular hendecagrams connected by equilateral triangles.

{11/2}, {11/3}, {11/4}, and {11/5}
Hendecagrammic prisms and  bipyramids
    
There are 4 hendecagrammic uniform prisms, and 6 hendecagrammic uniform antiprisms. The prisms are constructed by 4.4.11/q vertex figures, ![]()
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 Coxeter diagram. The hendecagrammic bipyramids, duals to the hendecagrammic prisms are also given.
| Symmetry | Prisms | |||
|---|---|---|---|---|
| D11h [2,11] (*2.2.11)  | 
![]() 4.4.11/2  | 
![]() 4.4.11/3  | 
![]() 4.4.11/4  | 
![]() 4.4.11/5  | 
| D11h [2,11] (*2.2.11)  | 
||||
Hendecagrammic antiprisms
    
The antiprisms with 3.3.3.3.11/q vertex figures, ![]()
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. Uniform antiprisms exist for p/q>3/2,[1] and are called crossed for p/q<2. For hendecagonal antiprism, two crossed antiprisms can not be constructed as uniform (with equilateral triangles): 11/8, and 11/9.
| Symmetry | Antiprisms | Crossed- antiprisms | ||
|---|---|---|---|---|
| D11h [2,11] (*2.2.11)  | 
![]() 3.3.3.11/2  | 
![]() 3.3.3.11/4  | 
![]() 3.3.3.11/6 3.3.3.-11/5  | 
Nonuniform 3.3.3.11/8 3.3.3.-11/3  | 
| D11d [2+,11] (2*11)  | 
![]() 3.3.3.11/3  | 
![]() 3.3.3.11/5  | 
![]() 3.3.3.11/7 3.3.3.-11/4  | 
Nonuniform 3.3.3.11/9 3.3.3.-11/2  | 
Hendecagrammic trapezohedra
    
The hendecagrammic trapezohedra are duals to the hendecagrammic antiprisms.
| Symmetry | Trapezohedra | ||
|---|---|---|---|
| D11h [2,11] (*2.2.11)  | 
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| D11d [2+,11] (2*11)  | 
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See also
    
    
References
    
- Skilling, John (1976), "Uniform Compounds of Uniform Polyhedra", Mathematical Proceedings of the Cambridge Philosophical Society, 79 (3): 447–457, doi:10.1017/S0305004100052440, MR 0397554.
 
- Coxeter, Harold Scott MacDonald; Longuet-Higgins, M. S.; Miller, J. C. P. (1954). "Uniform polyhedra". Philosophical Transactions of the Royal Society of London. Series A. Mathematical and Physical Sciences. The Royal Society. 246 (916): 401–450. doi:10.1098/rsta.1954.0003. ISSN 0080-4614. JSTOR 91532. MR 0062446. S2CID 202575183.
 









