cityrail ticket cubohemioctahedron
A while ago, as many of you would, I saw the Metrocard tricontahedron linked from the Makezine blog.
This weekend, whilst hacking away, I took a break and was distracted by the large pile of used tickets that have built up on my desk. I found the above site again, and spend about 15 minutes folding some tickets until I emerged to the loungeroom to show off the results.
(flickr)
So what it this shape actually called? I googled ‘tricontrahedron’
(because I can’t read) and then ‘tricontahedron’, and
discovered
that this name is derived from the prefix tri-, the modifier
conta- (which refers to a group of ten), and the suffix -hedron,
meaning “faces”, so we have a 30-faced polyhedra. True so far, but
actually googling or searching
Mathworld for
tricontahedron
wasn’t showing me any graphical evidence that this
was the right name. In fact, the closest by name, the rhombic
tricontahedron,
looks nothing like this shape.
But finally I stumbled on a set of excellent polyhedra sites:
- Anthony Thyssen’s Studies into Polyhedra
- V. Bulatov’s Polyhedra Collection
- George Hart’s Encyclopaedia of Polyhedra
Thanks to FreeWRL I managed to finally find the cubohemioctahedron, which although the image on that linked page doesn’t look terribly much like our shape, upon loading the VRML for the polyhedron I was able to convince myself that this is the one.