I55a_2 Vertex Coordinates Class A radius: 1.0 even permutations of ( ±sqrt( (5 + sqrt(5)) / 10 ), ±sqrt( (5 - sqrt(5)) / 10 ), 0 ) A01: 0.85065080835203993218 0.52573111211913360603 0.00000000000000000000 A02: 0.85065080835203993218 -0.52573111211913360603 0.00000000000000000000 A03: -0.85065080835203993218 0.52573111211913360603 0.00000000000000000000 A04: -0.85065080835203993218 -0.52573111211913360603 0.00000000000000000000 A05: 0.00000000000000000000 0.85065080835203993218 0.52573111211913360603 A06: 0.00000000000000000000 0.85065080835203993218 -0.52573111211913360603 A07: 0.00000000000000000000 -0.85065080835203993218 0.52573111211913360603 A08: 0.00000000000000000000 -0.85065080835203993218 -0.52573111211913360603 A09: 0.52573111211913360603 0.00000000000000000000 0.85065080835203993218 A10: -0.52573111211913360603 0.00000000000000000000 0.85065080835203993218 A11: 0.52573111211913360603 0.00000000000000000000 -0.85065080835203993218 A12: -0.52573111211913360603 0.00000000000000000000 -0.85065080835203993218 Class B radius R: sqrt(5) - 2, approx. 0.236067977500 even permutations of ( ±sqrt( (5 + sqrt(5)) / 10 ), ±sqrt( (5 - sqrt(5)) / 10 ), 0 ) * R B01: 0.20081141588622727987 0.12410828034667904629 0.00000000000000000000 B02: 0.20081141588622727987 -0.12410828034667904629 0.00000000000000000000 B03: -0.20081141588622727987 0.12410828034667904629 0.00000000000000000000 B04: -0.20081141588622727987 -0.12410828034667904629 0.00000000000000000000 B05: 0.00000000000000000000 0.20081141588622727987 0.12410828034667904629 B06: 0.00000000000000000000 0.20081141588622727987 -0.12410828034667904629 B07: 0.00000000000000000000 -0.20081141588622727987 0.12410828034667904629 B08: 0.00000000000000000000 -0.20081141588622727987 -0.12410828034667904629 B09: 0.12410828034667904629 0.00000000000000000000 0.20081141588622727987 B10: -0.12410828034667904629 0.00000000000000000000 0.20081141588622727987 B11: 0.12410828034667904629 0.00000000000000000000 -0.20081141588622727987 B12: -0.12410828034667904629 0.00000000000000000000 -0.20081141588622727987 Face Cycles Covering Faces A01 B02 A07 B08 A12 B11 A01 B05 A03 B10 A07 B09 A01 B06 A12 B03 A10 B05 A01 B09 A10 B07 A08 B02 A01 B11 A08 B12 A03 B06 A02 B01 A06 B05 A10 B09 A02 B07 A10 B04 A12 B08 A02 B08 A04 B12 A06 B11 A02 B09 A05 B10 A04 B07 A02 B11 A12 B06 A05 B01 A03 B04 A08 B07 A09 B10 A03 B05 A09 B01 A11 B06 A03 B12 A11 B08 A07 B04 A04 B03 A05 B06 A11 B12 A04 B08 A11 B02 A09 B07 A04 B10 A09 B05 A06 B03 A05 B03 A12 B04 A07 B10 A05 B09 A07 B02 A11 B01 A06 B01 A09 B02 A08 B11 A06 B12 A08 B04 A10 B03 Face Geometry Edge length (for unit outer radius) sqrt( (40 - 16 sqrt(5)) / 5 ), approx. 0.919011682189 Covering face angles arccos( (1 + 3 sqrt(5)) / 8 ), approx. 15.522487814070 degrees 2 Pi - arccos( (1 - 3 sqrt(5)) / 8 ), approx. 224.477512185930 degrees Dihedral angle arccos( -1 / 3 ), approx. 109.471220634491 degrees