Using method of virtual work, determine the angle $$ for equilibrium of the two$-$member linkage shown, with each link weight of $10$ N $.$

$($a$)11\mathrm{.}3,$

$($b$)21\mathrm{.}3,$

$($c$)32\mathrm{.}3,$

$($d$)63\mathrm{.}3,$

$($e$)$ none of the above $($show your answer$).$