A circular disk of unit radius is filled with a number of smaller circular disks arranged in the form of hexagon. Let `A_n` denotes a stack of disks arranged in the shape of a hexagon having 'n' disks on a side. The figure shows the configuration `A_3`. If A be the area of large disk, `S_n` be the number of disks in `A_n` configuration and `r_n` be the radius of each disk in `A_n` configuration, then `lim_(n->oo)(S_n)/n^2` `lim_(n->oo) nr_n`