The 12th Stellation of the Dodecahedron/Icosahedron Compound

I used Stella 4d to make this. You can try this program for yourself, for free, at this website.

Two Polyhedra Derived From the Icosahedron

The polyhedron above is a zonish icosahedron, with zones added to that Platonic solid based on its faces and vertices. Its faces are twenty equilateral triangles, thirty equilateral decagons, and sixty rhombi. After making it, I used faceting to truncate the vertices where sets of five rhombi met, creating the polyhedron below. It has twelve regular pentagons as faces, with the sixty rhombi of the polyhedron above turned into sixty isosceles triangles, along with the thirty decagons and twenty triangles from the first of these two polyhedra. This second one could be called either a faceted zonish icosahedron, or a truncated zonish icosahedron.

Both of these polyhedra were created using Stella 4d: Polyhedron Navigator, software you can try for free at http://www.software3d.com/Stella.php.

A Regular Icosagon, Split Into 180 Rhombi

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A Tessellation Featuring Regular Octadecagons, Regular Hexagons, and Equilateral Triangles, as Well as Right Trapezoids

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A Tessellation Featuring Regular Tetrakaiicosagons, Squares, Convex Pentagons, and Isosceles Triangles

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A Tessellation Featuring Regular Tetrakaiicosagons, Regular Dodecagons, Convex Pentagons, Rectangles, and Isosceles Triangles

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A Tessellation Featuring Regular Icosagons, Decagons, and Squares, Along With Rhombi, Other Quadrilaterals, and Isosceles Triangles

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A Symmetrohedron Featuring Eight Regular Hexagons, Six Squares, and 24 Isosceles Triangles

The isosceles triangles in this polyhedron have legs which are each 22.475% longer than their bases. I made this by creating the dual of the convex hull of the base/dual compound of the truncated octahedron, using a program called Stella 4d, which you can try for free right here.

The Compound of the Truncated Cube and the Rhombic Dodecahedron

This was created using Stella 4d: Polyhedron Navigator. You may try this program for free at this website.

The Tetrahedral Icosahedron

This is an icosahedron because it has twenty faces, and it is of tetrahedral symmetry. There are four regular hexagons and four equilateral triangles among these faces, along with twelve isosceles triangles with a leg:base length ratio of 1.73205:1. I found it while investigating variations to the base/dual compound of the truncated tetrahedron using Stella 4d, which you can try for free at this website. This polyhedron is the dual of the convex hull of the base/dual compound of the truncated tetrahedron and the triakis tetrahedron.