Answer
$F_R=257N$
$\phi=163^{\circ}$
Work Step by Step
$c=\sqrt{a^2+b^2}$
$F'=\sqrt{200^2+400^2}$
$F'=447.21N$
$\theta' = \arctan(200/400)=26.57^{\circ}$
$\phi=90^{\circ}-30^{\circ}-26.57^{\circ}=33.43^{\circ}$
$c=\sqrt{a^2+b^2-2*a*b*\cos(C)}$
$F_R=\sqrt{300^2+447.21^2-2*300*447.21*\cos(33.43^{\circ})}$
$F_R=257N$
$\sin33.43^{\circ} / 257.05 = \sin \theta/ 300$
$\theta= 40.02^{\circ}$
$\phi=90^{\circ}+40.02^{\circ}+33.43^{\circ}=163^{\circ}$
