Skip to main content

All Questions

Filter by
Sorted by
Tagged with
6 votes
1 answer
508 views

How many triangulations of a regular octahedron are there, without introducing new vertices?

It is easy to find three triangulations, each consisting of four tetrahedra. Are there more?
John Kieffer's user avatar
6 votes
1 answer
424 views

Probability of intersecting a rectangle with random straight lines

We are given a rectangle $R$ with sides lengths $r_1$ and $r_2$, contained in a square $S$, with sides lengths $s_1=s_2\ge r_1$ and $s_2=s_1\ge r_2$. $R$ and $S$ are axis-aligned in a cartesian plane $...
Penelope Benenati's user avatar
5 votes
2 answers
294 views

Convex caps with prescribed edges

Let $P$ be a convex polygon in the plane $R^2=R^2\times \{0\}$, and $E$ be the edge graph of some subdivision of $P$ into convex polygons, which is $3$-connected. Does there exist a convex polyhedral ...
Mohammad Ghomi's user avatar
5 votes
0 answers
213 views

Euclidean Minimum Spanning Trees Restricted to One Vertex Per Grid Cell

Given an $n \times n$ grid with unit grid cells, and one point from the interior of each cell, what is are best possible lower and upper bounds for lengths of minimum spanning trees? The lower bound ...
user avatar
4 votes
1 answer
1k views

Finding integer points on an N-d convex hull

Suppose we have a convex hull computed as the solution to a linear programming problem (via whatever method you want). Given this convex hull (and the inequalities that formed the convex hull) is ...
Michael Hoffman's user avatar