9 Dec
2002
9 Dec
'02
7:59 p.m.
Dan Hoey wrote:
"Shel Kaphan" <sjk@kaphan.org> asks:
A long time ago JHC gave (on math-fun) a nice way to see that the central angle of the icosahedron is atan(2) but I can't find or reproduce it :-( Does anyone still have that by any chance?
I don't know if this is it, but I think it's nice. [...]
That is a nice enough way to see *that* it is so, but not very explanatory (to me anyway) of why it turns out to be so. The explanation I referenced that was posted here a few years ago was a very satisfying one which I wish I hadn't lost track of! (If JHC is still listening perhaps he could re-post or re-generate it?)