The following pictures show n regular pentagons packed inside a unit equilateral triangle, so that the total sum of the sides of the pentagons is as large as possible.
1.
2.
3.
Σ s = 6/(3+3√5+√(6(5+√5))) = .36815+
Trivial.
Σ s = .50395+
Found by Jonathan Viquerat
in June 2026.
Σ s = .73031+
Found by Jonathan Viquerat
in June 2026.
4.
5.
6.
Σ s = .82930+
Found by Jonathan Viquerat
in June 2026.
Σ s = .92964+
Found by Jonathan Viquerat
in June 2026.
Σ s = 1.07719+
Found by Jonathan Viquerat
in June 2026.
7.
8.
9.
Σ s = 1.15736+
Found by Jonathan Viquerat
in June 2026.
Σ s = 1.23720+
Found by Jonathan Viquerat
in June 2026.
Σ s = 1.32596+
Found by Jonathan Viquerat
in June 2026.
10.
11.
12.
Σ s = 1.41659+
Found by Pedro Martins
in July 2026.
Σ s = 1.48404+
Found by Jonathan Viquerat
in June 2026.
Σ s = 1.55059+
Found by Jonathan Viquerat
in June 2026.
13.
14.
15.
Σ s = 1.61442+
Found by Jonathan Viquerat
in June 2026.
Σ s = 1.68627+
Found by Pedro Martins
in July 2026.
Σ s = 1.76065+
Found by Pedro Martins
in July 2026.
16.
17.
18.
Σ s = 1.81323+
Found by Joost de Winter
in September 2026.
Σ s = 1.86792+
Found by Pedro Martins
in July 2026.
Σ s = 1.92521+
Found by Joost de Winter
in September 2026.
19.
20.
21.
Σ s = 1.98444+
Found by Pedro Martins
in July 2026.
Σ s = 2.04069+
Found by Joost de Winter
in September 2026.
Σ s = 2.09694+
Found by Joost de Winter
in September 2026.
22.
23.
24.
Σ s = 2.13766+
Found by Joost de Winter
in September 2026.
Σ s = 2.18781+
Found by Joost de Winter
in September 2026.
Σ s = 2.22272+
Found by Joost de Winter
in October 2026.
25.
26.
27.
Σ s = 2.28871+
Found by Joost de Winter
in September 2026.
Σ s = 2.32778+
Found by Joost de Winter
in September 2026.
Σ s = 2.38202+
Found by Joost de Winter
in September 2026.
28.
29.
30.
Σ s = 2.43274+
Found by Joost de Winter
in September 2026.
Σ s = 2.46856+
Found by Joost de Winter
in September 2026.
Σ s = 2.49815+
Found by Joost de Winter
in October 2026.
31.
32.
33.
Σ s = 2.55258+
Found by Joost de Winter
in September 2026.
Σ s = 2.59323+
Found by Joost de Winter
in September 2026.
Σ s = 2.64274+
Found by Joost de Winter
in September 2026.
34.
35.
36.
Σ s = 2.67451+
Found by Joost de Winter
in October 2026.
Σ s = 2.72703+
Found by Joost de Winter
in September 2026.
Σ s = 2.77921+
Found by Joost de Winter
in September 2026.
37.
38.
39.
Σ s = 2.80598+
Found by Joost de Winter
in September 2026.
Σ s = 2.83595+
Found by Joost de Winter
in September 2026.
Σ s = 2.88052+
Found by Joost de Winter
in September 2026.
40.
41.
42.
Σ s = 2.91778+
Found by Joost de Winter
in September 2026.
Σ s = 2.94528+
Found by Joost de Winter
in October 2026.
Σ s = 2.98718+
Found by Joost de Winter
in September 2026.
43.
44.
45.
Σ s = 3.01900+
Found by Joost de Winter
in September 2026.
Σ s = 3.06208+
Found by Joost de Winter
in September 2026.
Σ s = 3.10421+
Found by Joost de Winter
in September 2026.
46.
47.
48.
Σ s = 3.13957+
Found by Joost de Winter
in September 2026.
Σ s = 3.16681+
Found by Joost de Winter
in September 2026.
Σ s = 3.20384+
Found by Joost de Winter
in September 2026.
49.
50.
Σ s = 3.22739+
Found by Joost de Winter
in October 2026.
Σ s = 3.24414+
Found by Joost de Winter
in October 2026.