Let $T=78N,a=5m,$ and $b=2m.$

Type the unit, $N,$ after typing your numerical answer.

$6$b$.$ The boom AE is supported by a ball$-$and$-$socket at A and

guy wires $CD$ and $FB.$ The magnitude of the mass $m$ of the

block at $E$ is unknown, but the tension in wire $FB$ is known to

be T$.$ Determine the magnitude of the vertical component of the

support force at $A.$