3
\includegraphics[max width=\textwidth, alt={}, center]{ba29ddb2-3558-4be1-a8a8-134e27a70149-04_456_767_260_689} Four coplanar forces act at a point. The magnitudes of the forces are \(20 \mathrm {~N} , 30 \mathrm {~N} , 40 \mathrm {~N}\) and \(F \mathrm {~N}\). The directions of the forces are as shown in the diagram, where \(\sin \alpha ^ { \circ } = 0.28\) and \(\sin \beta ^ { \circ } = 0.6\). Given that the forces are in equilibrium, find \(F\) and \(\theta\).