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Of the five polyhedra above, all appear to feature decagons. Upon close inspection, though, one of them actually features icosagons — with half their sides very short. Can you spot this polyhedron?
The next set of three polyhedra all feature pentadecagons.
That’s eight so far. Not enough!
Here are eight more, to round out the set of all sixteen, each of which I made using Stella 4d: Polyhedron Navigator. This program may be tried for free at http://www.software3d.com/Stella.php.