PROBLEM $2$

For the steel truss and loading shown, determine the minimum allowable dimensions of the cross section of truss members $\backslash ($ A B $\backslash )$ and $\backslash ($ B C $\backslash ).$ Both members must have the same cross$-$sectional area. The cross section must be square. The yield stress of the steel is $60$ ksi and the safety factor is $3\mathrm{.}0.$