\text { The boat shown in the following figure is to be pulled onto the shore using two ropes. If the resultant force } \text { is to be } F_{1}=80 \ell b \text { directed along the line aa, determine the magnitudes of the force } P \text { so that the } \text { magnitude of } P \text { is minimum. } T \text { acts at an angle } \theta_{1}=30^{\circ} \text { from the line aa. The force } P \text { will be minimum } \text { for a certain angle between } P \text { and } T \text {. }