Acronym sird TOCID symbol rd|ID Name small rhombidodecahedron ` © ©` Circumradius sqrt[sqrt(5)+11/4] = 2.232951 Vertex figure [10/9,4/3,10,4]/0 General of army srid Colonel of regiment srid Dihedral angles between {4} and {10} (at pseudo {3}):   arccos(-sqrt[(5-sqrt(5))/10]) = 121.717474° between {4} and {10} (at pseudo {5}):   arccos(sqrt[(5+sqrt(5))/10]) = 31.717474° Confer Grünbaumian relatives: sird+12{10/2}   sird+20{6/2} Externallinks

As abstract polytope sird is isomorphic to gird, thereby replacing decagons by decagrams.

This polyhedron is an edge-faceting of the small rhombicosidodecahedron (srid).

Incidence matrix according to Dynkin symbol

```reduced( x5/2x5x , by 12{10/2} )
or
reduced( x3/2x5x , by 20{6/2} )

60 |  2  2 |  2  2
---+-------+------
2 | 60  * |  1  1  at pseudo {3}
2 |  * 60 |  1  1  at pseudo {5}
---+-------+------
4 |  2  2 | 30  *
10 |  5  5 |  * 12

or (only as abstract polyhedron)
60 |   4 |  2  2
---+-----+------
2 | 120 |  1  1
---+-----+------
4 |   4 | 30  *
10 |  10 |  * 12
```