Triangle, n = 12 record

A = the smallest positive root of 729x6−291168x5+390241x4−43317x3−4386x2+5x+5
= 0.0310047817435254466386619953378577300655973679…
solved here as the exact critical point of the 3-parameter symmetry-reduced tie system (21 tied minimal triangles); minimal polynomial found by lattice reduction on 1650 digits and verified against a 3000-digit solution
21 minimal triangles in 4 congruence classes, colored by class.

Symmetry

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

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

Minimal triangles

21 triangles tied (within relative 10−9) at the minimal area, in 4 congruence classes:

countside lengthstriangles (point indices)
6 0.3082 · 0.4632 · 0.7528 (0,6,10) (1,2,10) (2,4,10) (2,5,6) (2,6,8) (6,9,10)
6 0.2502 · 0.7658 · 1.0057 (0,5,7) (0,5,11) (1,3,8) (1,7,8) (3,4,9) (4,9,11)
6 0.5751 · 0.6451 · 1.2160 (0,2,3) (1,6,11) (2,7,9) (3,5,10) (4,6,7) (8,10,11)
3 0.2502 · 0.2502 · 0.3770 (0,1,7) (3,8,9) (4,5,11)

Provenance

Record history

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