Skip to main content

All Questions

Filter by
Sorted by
Tagged with
54 votes
5 answers
2k views

Unusual symmetries of the Cayley-Menger determinant for the volume of tetrahedra

Suppose you have a tetrahedron $T$ in Euclidean space with edge lengths $\ell_{01}$, $\ell_{02}$, $\ell_{03}$, $\ell_{12}$, $\ell_{13}$, and $\ell_{23}$. Now consider the tetrahedron $T'$ with edge ...
6 votes
1 answer
539 views

Proofs of Euler's characteristic formula for n-Dim polytopes

Twenty proofs of Euler's formula V - E + F - 1 = 1, which applies to convex polyhedrons, i.e., 3-dimensional polytopes, are presented at the Geometry Junkyard. I'm interested in proofs of the more ...
3 votes
1 answer
153 views

Taking powers of polytopes

I am not sure this is a well framed question but I would like to know if anything like "taking the power" of a polytope is known. Imagine this situation where I want to think of such a thing : say ...