Skip to main content

All Questions

Filter by
Sorted by
Tagged with
1 vote
0 answers
68 views

Name of the perspector of the orthic triangle and excentral triangle

The orthic triangle and tangential triangles of a given triangle are in perspective. What's the official kimberling center associated with this perspector?
3 votes
1 answer
285 views

Name this kimberling center

The lines which connect the vertices of a triangle with the tangent points between the Spieker circle and the medial triangle are concurrent. Which kimberling center does this point correspond to?
2 votes
0 answers
84 views

Another variant of the Malfatti problem

We try to add to A Variant of the Malfatti Problem As stated in the Wikipedia entry on Malfatti circles, it is an open problem to decide, given a number $n$ and any triangle, whether a greedy method ...
6 votes
2 answers
215 views

Partition of polygons into 'strongly acute' and 'strongly obtuse' triangles

Definition: Let us refer to obtuse triangles with the largest angle strictly above a given cutoff value as 'strongly obtuse' - the definition is parametrized by the cutoff value. Likewise, strongly ...
3 votes
1 answer
152 views

Triangles that can be cut into mutually congruent and non-convex polygons

It is easy to note that an equilateral triangle can be cut into 3 mutually congruent and non-convex polygons (replace the 3 lines meeting at centroid and separating out the 3 congruent quadrilaterals ...
1 vote
0 answers
40 views

Tiling with a one-parameter family of non-congruent triangles

This post continues Tiling with triangles of same circumradius and inradius. The following are known about infinite sets of triangles that can be parametrized with one variable: from an infinite set ...
3 votes
1 answer
473 views

On 4 random points in a rectangle [closed]

Given a bounded rectangular area, I generate 4 random points. What is the probability that the fourth point lie within a triangle formed the first 3? How would I attack this problem? The goal is to ...
2 votes
2 answers
163 views

Maximum possible number of similar three-colored triangles

I want to maximize the number of similar triangles with vertices from three fixed sets, one vertex from each set. For example, if you fix two points $X$, $Y$ (i.e. two sets with only one member), then ...