Acronym ifbah, ike-6-2
Name 2-fold faceted icosahedron ike-6-2,
pentagonal butterfly wedge,
blend of 2 pentagonal pyramids,
half of blend of 2 pentagonal antiprisms
 
Circumradius sqrt[(5+sqrt(5))/8] = 0.951057
Vertex figures [33,5], [3,5,3/2,5/4]/0, and [32,5]
Lace city
in approx. ASCII-art 
 o   o 
   f   
x     x
Coordinates (τ/2, 1/2, 0)   & even permutations, all changes of sign, but last coordinate non-negative
where τ = (1+sqrt(5))/2
Dihedral angles
(at margins)
  • between {3} and {3}:   arccos(-sqrt(5)/3) = 138.189685°
  • between {3} and {5} type A:   arccos(-sqrt[(5-2 sqrt(5))/15]) = 100.812317°
  • between {3} and {5} type B & C:   arccos[(5+2 sqrt(5))/15] = 37.377368°
Face vector 8, 14, 8
Confer
uniform relative:
ike  
blend-component:
peppy  
compounds:
2pap-blend  
External
links 		polytopewiki  

This polyhedron either can be considered as a faceting of ike or else could be constructed as a blend from 2 copies of peppy, when taken coincident with a pair of triangles.


Incidence matrix

2 * * | 2 2 0 0 | 1 2 1  [3,3,3,5]
* 2 * | 2 0 2 0 | 2 2 0  [3,5,3/2,5/4]/0
* * 4 | 0 1 1 1 | 1 1 1  [3,3,5]
------+---------+------
1 1 0 | 4 * * * | 1 1 0  type A
1 0 1 | * 4 * * | 0 1 1
0 1 1 | * * 4 * | 1 1 0  type B
0 0 2 | * * * 2 | 1 0 1  type C
------+---------+------
1 2 2 | 2 0 2 1 | 2 * *  {5}
1 1 1 | 1 1 1 0 | * 4 *
1 0 2 | 0 2 0 1 | * * 2

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