Three Polyhedra Which Each Include 42 Regular Decagonal Faces

The first polyhedron shown here is also a symmetrohedron. 42 of its faces are regular decagons, and twenty are equilateral triangles. There are also sixty each of two types of isosceles trapezoids. That’s 182 faces in all.

The second polyhedron shown, below, also has 42 regular decagons as faces, along with twenty equiangular hexagons, sixty isosceles triangles, sixty almost-square isosceles trapezoids, and 120 of another kind of isosceles trapezoid. That’s a total of 302 faces.

The third one I found, shown below, has 42 decagons, sixty convex hexagons, twenty equilateral triangles, sixty rectangles, and sixty isosceles trapezoids, for a total of 242 faces.

I made all three of these polyhedra using Stella 4d: Polyhedron Navigator, which you can try for yourself, free, at

The Black Widow Tessellation

balck widow tessellation

The black polygons in this radial tessellation are regular decagons. The red figures are hourglass-shaped equilateral hexagons, which remind me of the distinctive red markings found on many black widow spiders.

A Polyhedron Featuring 42 Regular Decagons


In addition to the 42 regular decagons, the faces of this polyhedron include twenty equilateral triangles, sixty yellow trapezoids, and sixty blue trapezoids. That’s 182 faces in all.

The next picture shows what happens if all of the decagons have the same color, the triangles have another, and the trapezoids are hidden from view.


Both images were created using Stella 4d, software you can try for yourself at this website.

Decagonal Ring of Rhombic Triacontahedra

ring of ten Rhombic Triaconta

Ten rhombic triacontahedra fit perfectly into a decagonal ring. It’s not a “near-miss” — the fit is exact.

I made this with Stella 4d, software you can try for free, or purchase, at

There Are Many Faceted Versions of the Dodecahedron. This One Is the Dual of the Third Stellation of the Icosahedron.

Faceted Dodeca

The twelve purple faces of this faceted dodecahedron show up on Stella 4d‘s control interface as {10/4} star decagons, which would make them each have five pairs of two coincident vertices. I’m informally naming this special decagon-that-looks-like-a-pentagram (or “star pentagon,” if you prefer) the “antipentagram,” for reasons which I hope are clear.

Stella 4d, the program I use to make most of my polyhedral images, may be tried for free at