An equilateral prism of mass m rests an a rough horizontal surface with coefficient of friction µ. A horizontal force F is applied on the prism as shown in figure . If the coefficient of friction is sufficiently high so that the prism does not slide before toppling, the minimum force required to topple the prism is $\mathrm{F}=\frac{\mathrm{mg}}{\sqrt{\mathrm{x}}}$Then the value of x is____________________