The honeycomb conjecture, now proved, posited that a partition of the plane into regions of equal area has perimeter at least that of the regular hexagonal grid.

formulation date | 340 AD (1685 years ago) formulator | Pappus status | proved proof date | 1999 (1659 years later) (26 years ago) prover | Thomas Callister Hales

solved mathematics problems | mathematics theorems