A tie rod $(1)$and a pipe strut$(2)$are used to support a load P$=25$ kips. Pipe strut $(2)$ has an outside diameter of $6\mathrm{.}625$ in and a wall thickness of $0\mathrm{.}280$ in$.$ Both the tie rod and the pipe strutare made of structural steel with a modulus of elasticty E$=29000$ ksi and a yield strength ${}_y=36$ ksi. Fot the tie rod, the minimum factor $of$ safety with respect $to$ the yield $is1\mathrm{.}5$ and the maximum allowable axial elongation $is0\mathrm{.}30in.$ Assume that $a=21ft,b=9ft,$ and $c=27ft.a$