The generalized coordinates of a simple pendulum are the angular displacement \(\theta\) and the angular momentum \(m l^{2} \dot{\theta}\). Study, both mathematically and graphically, the nature of the corresponding trajectories in the phase space of the system, and show that the area \(A\) enclosed by a trajectory is equal to the product of the total energy \(E\) and the time period \(\tau\) of the pendulum.