Rectified truncated icosahedron

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Short description: Near-miss Johnson solid with 92 faces
Rectified truncated icosahedron
Rectified truncated icosahedron.png
TypeNear-miss Johnson solid
Faces92:
60 isosceles triangles
12 pentagons
20 hexagons
Edges180
Vertices90
Vertex configuration3.6.3.6 (3.6)^2 vertex.svg
3.5.3.6 3.5.3.6 vertex.svg
Schläfli symbolrt{3,5}
Symmetry groupIh, [5,3], (*532) order 120
Rotation groupI, [5,3]+, (532), order 60
Dual polyhedronRhombic enneacontahedron
Propertiesconvex
Net
Rectified truncated icosahedron net.png

In geometry, the rectified truncated icosahedron is a convex polyhedron. It has 92 faces: 60 isosceles triangles, 12 regular pentagons, and 20 regular hexagons. It is constructed as a rectified, truncated icosahedron, rectification truncating vertices down to mid-edges.

As a near-miss Johnson solid, under icosahedral symmetry, the pentagons are always regular, although the hexagons, while having equal edge lengths, do not have the same edge lengths with the pentagons, having slightly different but alternating angles, causing the triangles to be isosceles instead. The shape is a symmetrohedron with notation I(1,2,*,[2])

Images

截角半正三十二面體.gif

Dual

By Conway polyhedron notation, the dual polyhedron can be called a joined truncated icosahedron, jtI, but it is topologically equivalent to the rhombic enneacontahedron with all rhombic faces.

Related polyhedra

The rectified truncated icosahedron can be seen in sequence of rectification and truncation operations from the truncated icosahedron. Further truncation, and alternation operations creates two more polyhedra:

Name Truncated
icosahedron
Truncated
truncated
icosahedron
Rectified
truncated
icosahedron
Expanded
truncated
icosahedron
Truncated
rectified
truncated
icosahedron
Snub
rectified
truncated
icosahedron
Coxeter tI ttI rtI rrtI trtI srtI
Conway atI etI btI stI
Image Uniform polyhedron-53-t12.svg Truncated truncated icosahedron.png Rectified truncated icosahedron.png Expanded truncated icosahedron.png Truncated rectified truncated icosahedron.png Snub rectified truncated icosahedron.png
Net Truncated icosahedron flat.png Truncated truncated icosahedron net.png Rectified truncated icosahedron net.png Expanded truncated icosahedron net.png Snub rectified truncated icosahedron net.png
Conway dtI = kD kD kdtI jtI jtI otI mtI gtI
Dual Pentakis dodecahedron.png Kissed kissed dodecahedron.png Joined truncated icosahedron.png Ortho truncated icosahedron.png Meta truncated icosahedron.png Gyro truncated icosahedron.png
Net Pentakisdodecahedron net.png Kissed kissed dodecahedron net.png Rhombic enneacontahedron flat.png Ortho truncated icosahedron net.png Gyro truncated icosahedron net.png

See also

References

  • Coxeter Regular Polytopes, Third edition, (1973), Dover edition, ISBN 0-486-61480-8 (pp. 145–154 Chapter 8: Truncation)
  • John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, The Symmetries of Things 2008, ISBN 978-1-56881-220-5

External links