English

Almost similar configurations

Combinatorics 2019-05-14 v2 Metric Geometry

Abstract

Let h(n)h(n) denote the maximum number of triangles with angles between 5959^\circ and 6161^\circ in any nn-element planar set. Our main result is an exact formula for h(n)h(n). We also prove h(n)=n3/24+O(nlogn)h(n)= n^3/24+ O(n \log n) as nn\to \infty. However, there are triangles TT and nn-point sets PP showing that the number of ε\varepsilon-similar copies of TT in PP can exceed n3/15n^3/15 for any ε>0\varepsilon>0.

Keywords

Cite

@article{arxiv.1805.02072,
  title  = {Almost similar configurations},
  author = {Imre Bárány and Zoltán Füredi},
  journal= {arXiv preprint arXiv:1805.02072},
  year   = {2019}
}

Comments

24 pages, 11 figures (A slightly revised version, a bit more detailed calculations)

R2 v1 2026-06-23T01:45:59.074Z