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51 views

On triangulations and "coverage" of circumcircles

Let $P$ be a convex quadrilateral defined by four vertices $a$, $b$, $c$, and $d$. Suppose that the circumcircle of $\triangle abd$ contains $c$.* Let $D(\triangle abc)$ to denote the area enclosed by ...
Scattering State's user avatar
15 votes
1 answer
616 views

Acute triangles in "obtuse" polygons?

Let $P$ be a convex polygon. Suppose every interior angle of $P$ is obtuse. Is it always the case that there exist three vertices $p, q, r$ of $P$ such that $\triangle pqr$ is acute? I conjecture ...
Scattering State's user avatar
2 votes
1 answer
441 views

Build reversed No-Fit-Polygon

I need some robust algorithm to optimally fit one non-convex polygon into another. The destination one can contain holes. Recently I found scholarly articles on this subject: One of them describes ...
Sviatoslav Iakovlev's user avatar
4 votes
2 answers
805 views

Fitting one Polygon in another

I have two Polygons A and B and I want to find the position, rotation and scale of B, so it fits into A and has the maximum Area possible. Also both can be concave. I did some research but couldn't ...
Melodix's user avatar
  • 41
8 votes
2 answers
339 views

Angle subtended by the shortest segment that bisects the area of a convex polygon

Let $C$ be a convex polygon in the plane and let $s$ be the shortest line segment (I believe this is called a "chord") that divides the area of $C$ in half. What is the smallest angle that $s$ could ...
Tom Solberg's user avatar
6 votes
1 answer
2k views

Given a set of 2D vertices, how to create a minimum-area polygon which contains all the given vertices?

Not sure whether this question belongs here or math.stackexchange. You can assume that all the vertices are unique. The given vertices can be the vertices of the polygon, thus they do NOT have to be ...
fajrian's user avatar
  • 163
0 votes
2 answers
3k views

Determine the boundary points of a set of points [closed]

I have a set of points $S=\{(x_1,y_1),(x_2,y_2),\ldots,(x_n,y_n)\}$. Then how to find the boundary points (which is a subset of $S$) of $S$? There are methods like convex hull, concave hull and $\...
janak's user avatar
  • 17
10 votes
1 answer
9k views

Get Largest Inscribed Rectangle of a Concave Polygon

I'm looking for an algorithm to find a set of largest inscribed rectangles of a concave polygon where each rectangle must be collinear with one of the edges of the polygon. In other words, I want to ...
Josh C.'s user avatar
  • 325
20 votes
2 answers
25k views

Partitioning a polygon into convex parts

I'm looking for an algorithm to partition any simple closed polygon into convex sub-polygons--preferably as few as possible. I know almost nothing about this subject, so I've been searching on Google ...
user14059's user avatar
  • 201
9 votes
5 answers
13k views

Get a point inside a polygon

I have a 2D polygon of arbitrary geometry. I need to find any point that is inside of that polygon. Taking the center won't work, because the polygon might not be convex. Is there a way to quickly ...
user10306's user avatar
  • 201
3 votes
3 answers
2k views

Is there a simple criterion to determine if two parallelograms intersect?

Assume we are given two parallelograms in the plane. How can I check if their intersection is nonempty? Note that I do not need to actually find the intersection.
Philipp's user avatar
  • 979