Disk covering problem $r(3)$
The smallest value $r(3)$ such that $3$ disks of radius $r(3)$ can be arranged to cover the unit disk.
Value: $\frac{\sqrt{3}}{2}$ (≈0.8660254)
Updates
-
Lower bound: $\frac{\sqrt{3}}{2}$
(≈0.8660254)
Trivial or easy according to the secondary source.
[via Circles Covering Circles, Erich Friedman] -
Upper bound: $\frac{\sqrt{3}}{2}$
(≈0.8660254)
Trivial or easy according to the secondary source.
[via Circles Covering Circles, Erich Friedman]