The following pictures show n equilateral triangles with side 1 packed inside the smallest known square (of side length s).
1.
2.
3.
s = (√2+√6)/4 = .965+
Trivial.
s = √6/2 = 1.224+
Trivial.
s = √3/2+√6/4 = 1.478+
Found by Erich Friedman
in 1996.
4.
5.
6.
s = 1+1/√3 = 1.577+
Found by Erich Friedman
in 1996.
s = 1.803+
Found by Erich Friedman
in 1996.
s = 9/2–3√3/2 = 1.901+
Found by Erich Friedman
in 1996.
7.
8.
9.
s = 2
Found by Erich Friedman
in 1996.
s = 3√3/2–1/2 = 2.098+
Found by Erich Friedman
in 1996.
s = 2.287+
Found by Maurizio Morandi
in July 2008.
10.
11.
12.
s = 2.377+
Found by David W. Cantrell
in July 2002.
s = 2.490+
Found by Maurizio Morandi
in June 2008.
s = 2.558+
Found by Dominik Kamp
in April 2026.
13.
14.
15.
s = 2.595+
Found by David W. Cantrell
in July 2002.
s = 2.726+
Found by David W. Cantrell
in July 2002.
s = 2.82989+
Found by Jake Loyd
in June 2026.
16.
17.
18.
s = 2.9000+
Found by Ian Watson
in April 2026.
s = 2.982+
Found by Maurizio Morandi
in July 2008.
s = 3.051+
Found by Maurizio Morandi
in July 2008.
19.
20.
21.
s = 3.12929+
Found by Jake Loyd
in June 2026.
s = 3.2305+
Found by Ian Watson
in April 2026.
s = 3.31102+
Found by Thomas Schadt
in June 2026.
22.
s = 3.3757+
Found by Ian Watson
in April 2026.
23.
s = 3.4311+
Found by Ian Watson
in April 2026.
24.
s = 3.46780+
Found by Thomas Schadt
in June 2026.
25.
s = 3.537+
Found by David W. Cantrell
in August 2012.
26.
s = 3.575+
Found by Maurizio Morandi
in September 2008.
27.
s = 3.6726+
Found by Ian Watson
in April 2026.
28.
s = 3.75707+
Found by Jake Loyd
in June 2026.
29.
s = 3.81711+
Found by Jake Loyd
in June 2026.
30.
s = 3.86619+
Found by Jake Loyd
in June 2026.
31.
s = 3.93107+
Found by Jake Loyd
in June 2026.
32.
s = 3.97880+
Found by Jake Loyd
in June 2026.
33.
s = 4.05164+
Found by Jake Loyd
in June 2026.
34.
s = 4.09088+
Found by Jake Loyd
in June 2026.
35.
s = 4.14123+
Found by Jake Loyd
in June 2026.
36.
s = 4.20791+
Found by Jake Loyd
in June 2026.
37.
s = 4.26880+
Found by Jake Loyd
in June 2026.
38.
s = 4.32018+
Found by Jake Loyd
in June 2026.
39.
s = 4.36792+
Found by Jake Loyd
in June 2026.
40.
s = 4.41058+
Found by Jake Loyd
in June 2026.
41.
s = 4.46446+
Found by Jake Loyd
in June 2026.
42.
s = 4.51177+
Found by Thomas Schadt
in June 2026.
43.
s = 4.55035+
Found by Thomas Schadt
in June 2026.
44.
s = 4.60023+
Found by Thomas Schadt
in June 2026.
45.
s = 4.67749+
Found by Thomas Schadt
in June 2026.
46.
s = 4.72965+
Found by Thomas Schadt
in June 2026.
47.
s = 4.78204+
Found by Thomas Schadt
in June 2026.
48.
s = 4.82632+
Found by Thomas Schadt
in June 2026.