Rectified truncated icosahedron
{{Short description|Near-miss Johnson solid with 92 faces}}
{{Infobox polyhedron
| image = Rectified truncated icosahedron.png
| type = Near-miss Johnson solid
| faces = 92:
60 isosceles triangles
12 pentagons
20 hexagons
| edges = 180
| vertices = 90
| vertex_config = {{math|3.6.3.6}} 100px
{{math|3.5.3.6}} 100px
| schläfli = {{math|rt{3,5} }}
| wythoff =
| conway = {{math|atI}}{{Cite web|url=https://levskaya.github.io/polyhedronisme/?recipe=C400A1atI|title = PolyHédronisme}}
| coxeter =
| symmetry = {{math|I{{sub|h}}, [5,3], (*532)}} order 120
| rotation_group = {{math|I, [5,3]{{sup|+}}, (532),}} order 60
| dual = Rhombic enneacontahedron
| properties = convex
| vertex_figure =
| 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
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:
class=wikitable
!Name !Truncated !Rectified !Cantellated !Cantitruncated !Snub |
align=center
!Coxeter !rowspan=2|[https://levskaya.github.io/polyhedronisme/?recipe=C1000A1tI tI] !rowspan=2|[https://levskaya.github.io/polyhedronisme/?recipe=C1000A1ttI ttI] !rtI !rrtI !trtI !srtI |
align=center
![https://levskaya.github.io/polyhedronisme/?recipe=C1000A1atI atI] ![https://levskaya.github.io/polyhedronisme/?recipe=C1000A1aatI etI] ![https://levskaya.github.io/polyhedronisme/?recipe=C8000A1btI btI] ![https://levskaya.github.io/polyhedronisme/?recipe=C8000A1stI stI] |
align=center
!Image |80px |80px |80px |80px |80px |80px |
Net
|80px |80px |80px |80px | |80px |
---|
align=center
!Conway ! dtI = kD [https://levskaya.github.io/polyhedronisme/?recipe=C100A1kD kD] ! [https://levskaya.github.io/polyhedronisme/?recipe=C100A1kdtI kdtI] ! [https://levskaya.github.io/polyhedronisme/?recipe=C100A1jtI jtI] ! [https://levskaya.github.io/polyhedronisme/?recipe=C100A1otI otI] ! [https://levskaya.github.io/polyhedronisme/?recipe=C8000A1mtI mtI] ! [https://levskaya.github.io/polyhedronisme/?recipe=C8000A1gtI gtI] |
align=center
!Dual |80px |80px |80px |80px |80px |80px |
Net
|80px |80px |80px |80px | |80px |
See also
References
{{reflist}}
- 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
- [http://www.georgehart.com/virtual-polyhedra/conway_notation.html George Hart's Conway interpreter]: generates polyhedra in VRML, taking Conway notation as input
{{Near-miss Johnson solids navigator}}
{{Polyhedron-stub}}