$(12$ Points$)$ Figure $2$ shows a square that is restrained by three contact points. $f_1$ is a point contact

with friction coefficient $,$ while $f_2$ and $f_3$ are frictionless point contacts. If $c=0\mathrm{.}25$ and $h=0\mathrm{.}5,$ find

one value of $$ such that the grasp yields force closure.