P22 · Extremal configurations · Classic

The smallest triangle in a disc

2y0
0x2
VERIFIED CONSTRUCTIONthe smallest triangle
n = 7Current record · open

Place n points inside a circle of radius 1 so that the smallest triangle formed by any three of them is as large as possible.

Formal definition

  • ContainerThe container is a circle of radius 1 centred at (1, 1), so coordinates run from 0 to 2.
  • SubmissionExactly n points, no three collinear
  • ConstraintsEvery point lies inside the container 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

Heilbronn in a disc: MathWorld collects the known values, some in closed form, none proven; the proof techniques from the square version have not been carried over.

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.