To familiarize herself with a CNC milling machine, a friend wants to make some 12-sided gaming dice (regular dodecahedrons) out of solid aluminum. Her question: what is the dihedral angle between any two adjacent faces?

(In reply to re: solution by Bryan)

When I first heard of spherical trigonometry, by reading Lancelot Hogben's Mathematics in the Making (illustrated with lots of pictures), I wondered why it wasn't covered in H.S. trig courses (at least in the U.S.). It's of much use in converting astronomical coordinates, finding times of sunrise/set, etc. It seems a neglected area, as is the subject of continued fractions.

Posted by Charlie on 2003-03-31 10:21:09