$2\mathrm{.}105$ A $12-$lb circular plate of $7-$in$.$ radius is supported as shown by three wires, each of $25-$in$.$ length. Determine the tension in each wire,

knowing that $a=30.$

Fig. P$2\mathrm{.}105$

$2\mathrm{.}106$ Solve Prob. $2\mathrm{.}105,$ knowing that $a=45.$