A Variant of the Rhombic Enneacontahedron

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A Variation On the Rhombic Enneacontahedron

In the rhombic enneacontahedron, which is shown below, there are thirty narrow rhombi (shown in red) which separate twelve panels of five rhombi each (shown in yellow). This polyhedron is familiar to many people:

Zonohedrified Dodeca

As you can see, the rhombic enneacontahedron has three of these yellow panels meeting at some of its vertices, along with three of the red, narrow rhombi.

For this new variant, at the top of this post, the five-rhombi panels are rotated until only two of them (rather than three) meet at certain vertices, and the thirty red, narrow rhombi between the yellow five-rhombi panels are replaced by twenty equilateral (but non-equiangular) hexagons, also shown in red.

Both of these polyhedra are related to the Platonic dodecahedron, which is shown below. In the rhombic enneacontahedron, the red, narrow rhombi correspond in position to the thirty edges of a dodecahedron. In the new variant, the red hexagons correspond to the vertices of a dodecahedron, rather than its edges. In both of these red-and-yellow polyhedra, the yellow, five-rhombi panels correspond to the dodecahedron’s faces. To see this more clearly, just compare the polyhedra above with this dodecahedron:

Dodecahedron

(All polyhedral images here were created with Stella 4d: Polyhedron Navigator, which you can try and/or buy here.)

Icosahedral Cluster of Dodecahedra

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Icosahedral Cluster of Dodecahedra

Software credit: http://www.software3d.com/stella.php

Dodecahedral Cluster of Icosidodecahedra

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Dodecahedral Cluster of Icosidodecahedra

Created using Stella 4d, software you can try at http://www.software3d.com/stella.php.

A Dodecahedron, with Mandalas in Six Colors

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Dodecahedron with Mandalas in Six Colors

Geometer’s Sketchpad and MS-Paint were used to create a black-and-white version of the flat image (seen in the previous post) on each face of this dodecahedron. The rest of the work to made this 3-d rotating image was done with Stella 4d, which you can try for yourself at http://www.software3d.com/Stella.php.

Mandala-Decorated Dodecahedron

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Mandala-Decorated Dodecahedron

See http://www.software3d.com/stella.php to download a trial or fully-functioning version of the program (Stella 4d) I used to create this rotating image of a dodecahedron. Any image can be placed on a polyhedron’s faces with this program; this one appears two posts ago, and was made using Geometer’s Sketchpad and MS-Paint.

Dodecahedron Made of Rhombic Triacontahedra

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Dodecahedron Made of Rhombic Triacontahedra

In the last post, I showed that five rhombic triacontahedra can be stuck together to form a pentagonal ring. The next logical step is shown here: using such pentagonal rings to construct an entire dodecahedron made of rhombic triacontahedra.

Software credit: see http://www.software3d.com/stella.php.

Dodecahedron with Turquoise Stars

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Dodecahedron with Turquoise Stars

Programs used: Geometer’s Sketchpad and MS-Paint, to make the turquoise stars; and Stella 4d, to place that image of each face of this polyhedron, and then make this rotating .gif file.

Stella 4d may be tried for free at http://www.software3d.com/stella.php.

Sunrise Dodecahedron

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Sunrise Dodecahedron

Stella 4d (polyhedral manipulation software) was used to place the image in the previous post on each face of a dodecahedron. The program can do many other things as well — and you may try it for free at http://www.software3d.com/stella.php.

Two Saturnian Moons Adorning a Rhombic Dodecahedron

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Two Saturnian Moons Adorning a Rhombic Dodecahedron

The larger moon shown, Saturn’s largest, is Titan, recognizable by its hazy atmosphere. The smaller one, which looks more like our own moon, is Rhea.

This image was captured by the Cassini spacecraft, which has been investigating the Saturnian system now for years.

Projecting the images onto the faces of a rhombic dodecahedron was done with Stella 4d, software you may try for free at http://www.software3d.com/stella.php.

Dodecahedron Made of Hexagons

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Dodecahedron Made of Hexagons

There’s no immediately obvious connection between hexagons and dodecahedra. I was therefore surprised when I ran into this while playing around with Stella 4d, a program which allows easy polyhedron manipulation. (See www.software3d.com/stella.php for free trial download.) Hexagons, it turns out, work perfectly well to trace out the edges of a dodecahedron, and they need not even be regular to do so.