Zonohedra with surprisingly large numbers of faces are easy to make with Stella 4d: Polyhedron Navigator. This program is sold at http://www.software3d.com/Stella.php, where there is also a free trial download offered.
Software used to make these gifs: Stella 4d, available here.
Zonohedra are a subset of polyhedra. In a zonohedron, all the faces are zonogons. A zonogon is a polygon with an even number of sides, as well as having opposite sides both congruent and parallel. This small collection of rotating zonohedra was made using Stella 4d, a program you can try for yourself at this website.
Also, if you want to see a larger version of any one of these zonohedra, simply click on it.
Manipulating known polyhedra in the effort to find new ones, as I did here, is made easy with Stella 4d, a program available at this website.
I used Stella 4d to make this zonohedron. This program may be tried for free at http://www.software3d.com/Stella.php.
These polyhedral images were created with Stella 4d, a program you may try for free at this website.
In a recent post, I showed many images of zonohedra, then challenged readers to figure out, from the images, what zonohedra are: polyhedra with only zonogons as faces. Zonogons, I then explained, are polygons with (A) even numbers of edges, and with opposite edges always (B) congruent and (C) parallel. Here is another collection of zonohedra. (Individual images may be enlarged with a click.)
The next set of polyhedra shown, below, are not true zonohedra (as all the ones above are), but merely “zonish polyhedra.” From examination of the pictures above and below, can you figure out the difference between zonohedra and zonish polyhedra?
When you are ready to see the solution to the puzzle, simply scroll down.
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While zonohedra have only zonogons as faces, this restriction is “loosened” for zonish polyhedra. Such solids are formed by zonohedrifying non-zonohedral polyhedra, and letting at least some of the faces of the resulting polyhedra remain non-zonogonal. Zonish polyhedra are called “zonish” because many (usually most) of their faces are zonogons, but not all of them — in each case, some non-zonogonal polygons (such as triangles and/or pentagons, with their odd numbers of edges) do appear. Non-zonogonal polygons are not required to have odd numbers of edges, of course: simply having opposite edges be parallel, but of different lengths, is enough to prevent a polygon (such as a hexagon, octagon, or decagon) from being a zonogon.
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Software credit: I used Stella 4d to make these images. This program may be tried for free at this website.
Every zonohedron is a polyhedron, but not all polyhedra are zonohedra. Examples of zonohedra appear below. If you don’t already know what zonohedra are, can you figure out the definition from the examples shown, before reading the definition below the pictures?
Answer below (scroll down a bit):
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Zonohedra are polyhedra with only zonogons as faces. A zonogon is a polygon with an even number of sides, and also with opposite sides congruent and parallel.
Software credit: I used Stella 4d to make these virtual, rotating zonohedra. This program may be tried for free at http://www.software3d.com/Stella.php.
This zonohedron contains faces which are regular decagons (12 of them), equilateral octagons (30, all of the same type), equilateral hexagons (380 of them, of 7 types, with one of these 7 types, of which there are 20, being regular), squares (60), and non-square rhombi (480 of 8 types, counting reflections as separate types). With each polygon-type, including the reflections, given a different color, this zonohedron looks like this.
If reflected face-types are not counted as separate types, then the coloring-by-face-type uses four fewer colors, and looks like this:
Another view simply colors faces by numbers of sides, and is shown below. Each of these rotating images was created with Stella 4d, a program you may buy, or try for free, at http://www.software3d.com/Stella.php.
The polyhedron above is a 522-faced zonish polyhedron, which resembles, but is not identical to, a zonohedron. True zonohedra are recognizable as that type of polyhedron by their exclusively zonogonal faces. Zonogons are polygons with even numbers of sites, and with opposite sides both congruent and parallel. If you examine the polyhedron above carefully, you’ll find it does not follow these rules. Stella 4d, the polyhedral-manipulation software I use to make these images, allows one to create either a true zonohedron, or a mere “zonish” polyhedron, as the user chooses, starting from another polyhedron (which may, itself, be zonish, a true zonohedron, or neither).
The next polyhedron is the dual of the polyhedron above. This dual has 920 faces. The duals of both zonohedra and zonish polyhedra have a distincive appearance, but, to my knowledge, no one has yet given either set of polyhedra a single-word name. In my opinion, such names are both needed, and deserved.
If you would like to try Stella 4d for yourself, there is a free trial download available at http://www.software3d.com/Stella.php.
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