Acronym si
Name snub icosahedron,
compound of 10 oct (but not gissi)
 
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Circumradius 1/sqrt(2) = 0.707107
Inradius 1/sqrt(6) = 0.408248
Vertex figure [34]
Dihedral angles
(at margins)
  • between {3} and {3}:   arccos(-1/3) = 109.471221°
Confer gissi   addasi  
External
links
hedrondude   wikipedia  

It can be obtained by placing 10 oct, thought of as triagular antiprisms, within an ike (in each of the axial orientations) with base-faces oriented in the same way as for the ike.

A double cover of si occurs as special case of addasi.


Incidence matrix

 60 |  2  2 |  3  1 ||  1
----+-------+-------++---
  2 | 60  * |  1  1 ||  1
  2 |  * 60 |  2  0 ||  1
----+-------+-------++---
  3 |  1  2 | 60  * ||  1
  3 |  3  0 |  * 20 ||  1
----+-------+-------++---
 6 |  6  6 |  6  2 || 10

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