Re: [math-fun] 24-cell --- it sez 'ere ...

Isn't a triangle the only proper polygon that is also a simplex, with or without the self-dual condition? Tom Dan Asimov writes:

Adam P. Goucher <apgoucher@gmx.com> wrote:

|Self-dual.

Good point — had never seen that particular distinction before.

For that matter, the triangle is the only self-dual convex Euclidean polytope that is *both* a polygon and a simplex.

--Dan