Packing $8$ unit circles in an equilateral triangle
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The side length of the smallest equilateral triangle into which $8$ unit circles can be packed.
Value: $2+2\sqrt{3}+\frac{2\sqrt{33}}{3}$ (≈9.29381)
Updates
-
Upper bound: $2+2\sqrt{3}+\frac{2\sqrt{33}}{3}$
(≈9.29381)
Reference unknown
[via Circles in Triangles, Erich Friedman] -
1993-12
Lower bound: $2+2\sqrt{3}+\frac{2\sqrt{33}}{3}$
(≈9.29381)
Melissen, H. (1993). Densest packings of congruent circles in an equilateral triangle. The American Mathematical Monthly, 100(10), 916-925.
[via Circles in Triangles, Erich Friedman]