Skip to main content

All Questions

Filter by
Sorted by
Tagged with
20 votes
0 answers
433 views

Is the dodecahedron flexible (as a polytope with fixed edge-lengths)?

Consider the (regular) dodecahedron $D\subset\Bbb R^3$. I want to continuously deform it so that throughout the deformation it stays a convex polytope, it stays a combinatorial dodecahedron (i.e. its ...
M. Winter's user avatar
  • 13.6k
13 votes
0 answers
378 views

Is a convex polyhedron determined by its edge lengths and angular defects?

Let's consider 3-dimensional convex polyhedra $P\subset\Bbb R^3$. The angular defect at a vertex $v$ is $2\pi$ minus the sum of the interior angles of the incident faces at $v$. Question: Is a ...
M. Winter's user avatar
  • 13.6k
11 votes
1 answer
652 views

How to correctly state Cauchy's rigidity theorem?

Cauchy's rigidity theorem is often stated briefly as Any two (convex, 3-dimensional) polyhedra with pairwise congruent faces are themselves congruent. As a more formal generalization to general ...
M. Winter's user avatar
  • 13.6k
5 votes
3 answers
683 views

Alexandrov's generalization of Cauchy's rigidity theorem

Wikipedia states that A. D. Alexandrov generalized Cauchy's rigidity theorem for polyhedra to higher dimensions. The relevant statement in the article is not linked to any source. The sources at the ...
M. Winter's user avatar
  • 13.6k