P29 · Extremal configurations · Classic

Heilbronn's problem in a triangle

1y0
0x1
VERIFIED CONSTRUCTIONthe smallest triangle
n = 6Current record · open

Place n points inside the right triangle with vertices (0, 0), (1, 0) and (0, 1), maximizing the smallest triangle formed by any three of them.

Formal definition

  • ContainerA right triangle with vertices (0, 0), (1, 0) and (0, 1): the region x ≥ 0, y ≥ 0, x + y ≤ 1
  • SubmissionExactly n points, no three collinear
  • ConstraintsEvery point lies inside the triangle or on its boundary
  • ObjectiveMake the smallest triangle over all triples as large as possible; compared internally by twice the area, exactly

Getting a feel for it

Where the room for improvement is

Even spreading is not enough: no three points may come close to collinear, and near-collinearity is exactly what tidy arrangements love to do. Optima are often asymmetric and hard even to guess.

Where the frontier is

n = 5 and 6 were proven by Yang, Zhang and Zeng, n = 7 by Sudermann-Merx — see arXiv:2607.15021; everything from n = 8 up is open.

Source
ONE LEADERBOARD PER n

Current best solutions by n

Each n is an independent record with a page of its own. Open any of them to inspect the current construction, then challenge it.