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{{Distinguish|Triakis truncated tetrahedron|Triakis tetrahedron}}
{| border="1" bgcolor="#ffffff" cellpadding="5" align="right" style="margin-left:10px" width="250"
{{refimprove|date=September 2014}}
!bgcolor=#e7dcc3 colspan=2|Truncated triakis tetrahedron
{{Short description|Near-miss Johnson solid with 16 faces}}
|-
{{Infobox polyhedron
|align=center colspan=2|[[Image:Truncated triakis tetrahedron.png|240px|Truncated triakis tetrahedron]]
| image = Truncated triakis tetrahedron.png
|-
| type = [[Near-miss Johnson solid]]
|bgcolor=#e7dcc3|Type||[[Conway polyhedron notation|Conway polyhedron]]
| faces = 4 [[hexagon]]s<br>12 irregular [[pentagon]]s
|-
| edges = 42
|bgcolor=#e7dcc3|Faces||4 [[hexagon]]s<br>12 [[pentagon]]s
| vertices = 28
|-
| vertex_config = {{math|4 (5.5.5)<BR>24 (5.5.6)}}
|bgcolor=#e7dcc3|Edges||42
| schläfli =
|-
| wythoff =
|bgcolor=#e7dcc3|Vertices||28
| conway = {{math|1=t6kT = dk6tT}}
|-
| coxeter =
|bgcolor=#e7dcc3|Dual|[[Hexakis truncated tetrahedron]]
| symmetry = {{math|''T''<sub>''d''</sub>}}
|-
| rotation_group =
|bgcolor=#e7dcc3|[[Vertex configuration]]||4 (5.5.5)<BR>24 (5.5.6)
| dual = [[Hexakis truncated tetrahedron]]
|-
| properties = [[convex polytope|convex]]
|bgcolor=#e7dcc3|[[List of spherical symmetry groups|Symmetry group]]||T<sub>d</sub>
| vertex_figure =
|-
| net = Conway_dk6tT_net.png
|bgcolor=#e7dcc3|Properties||[[Convex polytope|convex]]
|}
}}
[[Image:Truncated triakis tetrahedron.gif|thumb]]
The '''truncated triakis tetrahedron''' is a convex polyhedron with 16 faces: 4 sets of 3 [[pentagon]]s arranged in a [[Tetrahedral symmetry|tetrahedral]] arrangement, with 4 [[hexagon]]s in the gaps. It is constructed from taking a [[triakis tetrahedron]] by [[Truncation (geometry)|truncating]] the order-6 vertices. This creates 4 regular hexagon faces, and leaves 12 irregular pentagons.


In [[geometry]], the '''truncated triakis tetrahedron''', or more precisely an '''order-6 truncated triakis tetrahedron''', is a convex [[polyhedron]] with 16 [[Face (geometry)|faces]]: 4 sets of 3 [[pentagon]]s arranged in a [[Tetrahedral symmetry|tetrahedral]] arrangement, with 4 [[hexagon]]s in the gaps.
A topologically similar [[equilateral]] polyhedron can be constructed by using 12 [[Regular polygon|regular]] pentagons with 4 [[equilateral]] but nonplanar hexagons, each vertex with [[internal angle]]s alternating between 108 and 132 degrees.

== Construction ==
It is constructed from a [[triakis tetrahedron]] by [[Truncation (geometry)|truncating]] the order-6 vertices. This creates 4 regular hexagon faces, and leaves 12 mirror-symmetric pentagons.

[[File:triakistetrahedron.jpg|thumb|center|[[Triakis tetrahedron]]]]

A topologically similar [[equilateral]] polyhedron can be constructed by using 12 [[Regular polygon|regular]] pentagons with 4 [[equilateral]] but [[Skew polygon|nonplanar]] hexagons, each vertex with [[internal angle]]s alternating between 108 and 132 degrees.

Topologically, as a [[near-miss Johnson solid]], the four hexagons corresponding to the face planes of a tetrahedron are triambi, with equal edges but alternating angles, while the pentagons only have reflection symmetry.

==Full truncation==
If all of a triakis tetrahedron's vertices, of both kinds, are truncated, the resulting solid is an irregular icosahedron, whose dual is a ''trihexakis truncated tetrahedron''.

{{Anchor|order-3 truncated triakis tetrahedron}}Truncation of only the 3-valence vertices yields the '''order-3 truncated triakis tetrahedron''', which looks like a [[tetrahedron]] with each face raised by a low triangular [[frustum]]. The dual to that truncation will be the [[triakis truncated tetrahedron]].

[[File:StellaTruncTriakisTetra.png|160px|The full truncation]]

== Hexakis truncated tetrahedron ==
[[File:Hexakis_truncated_tetrahedron.gif|thumb|Hexakis truncated tetrahedron rotating]]
The dual of the ''order-6 Truncated triakis tetrahedron'' is called a '''hexakis truncated tetrahedron'''. It is constructed by a [[truncated tetrahedron]] with [[hexagonal pyramid]]s augmented. If all of the triangles are made regular, the polyhedron becomes a [[Near-miss Johnson solid|failed Johnson solid]], with coplanar triangles in a truncated tetrahedron volume.
{| class=wikitable
|- align=center
|[[File:Polyhedron truncated 4a max.png|160px]]<BR>[[truncated tetrahedron]]
|[[File:Conway_k6tT.png|160px]]<BR>Hexakis truncated tetrahedron
|[[File:Conway_k6tT_net.png|160px]]<BR>Net
|}


==Full Truncation==
A Triakis Tetrahedron can be fully truncated, not giving out this. The Full truncation is a special type of icosahedron, rather than a hexadecahedron. Another alternate truncation, or the "Low order truncation", will give out what looks like a [[Tetrahedron]] with each face raised by a low [[Pyramidal frustum|Triangular frustum]]. The dual to that truncation will be the "Triakis Truncated Tetrahedron". However, the full truncation is dual to a ''Trihexakis truncated tetrahedron''.
[[Image:Truncated triakis tetrahedron.png|240px|The common truncation]] [[File:StellaTruncTriakisTetra.png|120px|The Full Truncation]]
== See also ==
== See also ==
* [[Near-miss Johnson solid]]
* [[Near-miss Johnson solid]]
* [[Truncated tetrakis cube]]
* [[Truncated triakis octahedron]]
* [[Truncated triakis icosahedron]]


== External links ==
== External links ==
* [http://www.orchidpalms.com/polyhedra/acrohedra/nearmiss/jsmn.htm Johnson Solid Near Misses: Number 23]
* [http://www.orchidpalms.com/polyhedra/acrohedra/nearmiss/jsmn.htm Johnson Solid Near Misses: Number 22]
* [http://www.georgehart.com/virtual-polyhedra/conway_notation.html George Hart's Polyhedron generator] - "t6dtT" ([[Conway polyhedron notation]])
* [http://www.georgehart.com/virtual-polyhedra/conway_notation.html George Hart's Polyhedron generator] - "t6kT" ([[Conway polyhedron notation]])


{{Near-miss Johnson solids navigator}}
{{Near-miss Johnson solids navigator}}


{{DEFAULTSORT:Truncated Triakis Tetrahedron}}
[[Category:Polyhedra]]
[[Category:Polyhedra]]
[[Category:Truncated tilings]]


{{Polyhedron-stub}}


{{Polyhedron-stub}}
[[fr:triakitétraèdre tronqué]]
[[eo:Senpintigita trilateropiramidigita kvaredro]]

Latest revision as of 14:13, 29 September 2023

Truncated triakis tetrahedron
TypeNear-miss Johnson solid
Faces4 hexagons
12 irregular pentagons
Edges42
Vertices28
Vertex configuration4 (5.5.5)
24 (5.5.6)
Conway notationt6kT = dk6tT
Symmetry groupTd
Dual polyhedronHexakis truncated tetrahedron
Propertiesconvex
Net

In geometry, the truncated triakis tetrahedron, or more precisely an order-6 truncated triakis tetrahedron, is a convex polyhedron with 16 faces: 4 sets of 3 pentagons arranged in a tetrahedral arrangement, with 4 hexagons in the gaps.

Construction

[edit]

It is constructed from a triakis tetrahedron by truncating the order-6 vertices. This creates 4 regular hexagon faces, and leaves 12 mirror-symmetric pentagons.

Triakis tetrahedron

A topologically similar equilateral polyhedron can be constructed by using 12 regular pentagons with 4 equilateral but nonplanar hexagons, each vertex with internal angles alternating between 108 and 132 degrees.

Topologically, as a near-miss Johnson solid, the four hexagons corresponding to the face planes of a tetrahedron are triambi, with equal edges but alternating angles, while the pentagons only have reflection symmetry.

Full truncation

[edit]

If all of a triakis tetrahedron's vertices, of both kinds, are truncated, the resulting solid is an irregular icosahedron, whose dual is a trihexakis truncated tetrahedron.

Truncation of only the 3-valence vertices yields the order-3 truncated triakis tetrahedron, which looks like a tetrahedron with each face raised by a low triangular frustum. The dual to that truncation will be the triakis truncated tetrahedron.

The full truncation

Hexakis truncated tetrahedron

[edit]
Hexakis truncated tetrahedron rotating

The dual of the order-6 Truncated triakis tetrahedron is called a hexakis truncated tetrahedron. It is constructed by a truncated tetrahedron with hexagonal pyramids augmented. If all of the triangles are made regular, the polyhedron becomes a failed Johnson solid, with coplanar triangles in a truncated tetrahedron volume.


truncated tetrahedron

Hexakis truncated tetrahedron

Net

See also

[edit]
[edit]