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:
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.