Triangle, n = 22 record

A = the smallest positive root of 4113894419667609830181603x22+29807468238423455008126578x21−39085790603220143290920177x20+24488515905115680120305898x19−10736525499024455231632668x18+3768816750540027903994113x17−1158442379073845833748328x16+324799853969658361401171x15−71937195458392144391355x14+11920737923277897236508x13−1491784289359000650099x12+155491081480323732357x11−18192256172188373745x10+1431857137555076508x9−104692732480960029x8+11430606627963063x7−705604556304666x6+16028440098039x5+15064749231x4−2374399435x3−25225143x2+119664x+2704
= 0.0102661276072629636732082937422183376425520208…
solved here as the exact critical point of the 6-parameter symmetry-reduced tie system (39 tied minimal triangles); minimal polynomial found by lattice reduction on 1650 digits and verified against a 3000-digit solution
39 triangles tie for the minimal area.

Symmetry

3-fold dihedral symmetry (group D3, order 6).

22 points in 5 orbits (6 + 6 + 6 + 3 + 1) — hover a point to see its orbit.

Minimal triangles

39 triangles tied (within relative 10−9) at the minimal area, in 7 congruence classes:

countside lengthstriangles (point indices)
6 0.1581 · 0.1620 · 0.2861 (0,9,13) (1,10,12) (2,11,15) (3,6,14) (4,7,17) (5,8,16)
6 0.1620 · 0.4062 · 0.5624 (0,13,21) (1,12,21) (2,15,21) (3,14,21) (4,17,21) (5,16,21)
6 0.3853 · 0.5851 · 0.9694 (0,8,12) (1,11,13) (2,10,14) (3,7,15) (4,6,16) (5,9,17)
6 0.3600 · 0.6652 · 1.0244 (0,6,18) (1,7,18) (2,8,19) (3,9,19) (4,10,20) (5,11,20)
6 0.2861 · 0.8273 · 1.1126 (0,9,11) (1,8,10) (2,7,11) (3,6,10) (4,7,9) (5,6,8)
6 0.3122 · 0.8510 · 1.1625 (6,13,19) (7,12,20) (8,15,20) (9,14,18) (10,17,18) (11,16,19)
3 0.4062 · 0.4062 · 0.8108 (0,3,21) (1,4,21) (2,5,21)

Provenance

Record history

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