On 12/14/2013 06:07 PM, Richard Tobin wrote: > In article <firstname.lastname@example.org>, > quasi <email@example.com> wrote: > >> If a pentagon inscribed in a unit circle has rational edge >> lengths, then for some reordering of the edges within the >> circle, some diagonal has rational length. > > What do you make of > > radius 168: 53 91 187 292 294 > > -- Richard >
I find that it's a tiny bit off, when adding up the angles. The half-edges are: 53/2, 91/2, 187/2, 292/2 and 294/2.
If theta_j is the j'th half-angle for the j'th isosceles triangles, j = 1 ... 5, then