Question $2$

$($a$)$ State the Varignon's Theorem using a suitable sketch.

$[02]$

$($b$)$ A $2\mathrm{.}4$ m boom is held by a ball and socket joint at C and by two cables $AD$ and $AE$ as shown in Figure Q$2($a$).$ Determine the tension in each cable and the reaction at C$.[12]$