Answer
$a).$ The tension depends on (3) both the tree separation and the sag.
$b).$ $613N$
Work Step by Step
a). The tension depends on (3) both the tree separation and the sag.
b). Vertically, $2Tsin\theta-mg=0$
$T=\frac{mg}{2sin\theta}$
Horizontally, $Tcos\theta-Tcos\theta=0$
$\theta=tan^{-1}\frac{0.2}{5}=2.29^{\circ}$
So, $T=\frac{mg}{2sin\theta}=\frac{5\times9.8}{2sin2.29^{\circ}}=613N$