You can read a bit about the companyâs history in this article, but I canât point you to the companyâs web site for the simple reason that it doesnât have one. Yes, as amazing as this is, here in mid-2009 Arca Swiss lacks a web site, one of the few companies of any size in the photographic industry without one.
A pyritohedron is a dodecahedron with pyritohedral (T h) symmetry. Like the regular dodecahedron, it has twelve identical pentagonal faces, with three meeting in each of the 20 vertices. However, the pentagons are not constrained to be regular, and the underlying atomic arrangement has no true fivefold symmetry axes.
The unique regular hexahedron is the cube, and there are two hexahedra that can be built from regular polygons with equal edge lengths: the regular triangular dipyramid the pentagonal pyramid. Through graph duality, the list of numbers of vertices for each polyhedron in a hexahedron corresponds to the degree sequence (sequence of vertex degrees) of a hexahedral graph. The following table lists the hexahedra, together with their degree sequences, number of vertices , and number of edges , which are related through the polyhedral formula.