Select a single$-$angle equallegs tension member to resist a design load of $55$ kips $(P_u=55$kip $).$

The member is to be $20$ ft $.$ long, assume an end connection consisting of $(3)\frac{3}{4}-in$ bolts, $3-$inon center as shown in the Figure. Design a $3\frac{1}{2}$ X$3\frac{1}{2}$ in$.$ size angle $($L $3\frac{1}{2}$ X $3\frac{1}{2}$ X $?)$ tension

member using AISC$-$LRFD specifications and A$36$ steel with Fy $=36$ksi.

$P_u=55$kips$P_u=55$kips