Example $2\mathrm{.}7$ Two bars $1$ and $2$ are attached at A and $B$ to a wall by smooth pins. They are pin$-$connected at $C$ and subjected to a weight $W($Fig$.2\mathrm{.}16$a$).$

Calculate the forces in the bars.

SA$.$

d

Fig. $2\mathrm{.}16$