It was calculated that a shell when fired from a gun with a certain velocity and at an angle of elevation 5π 36 rad should strike a given target. In actual practice, it was found that a hill just prevented the trajectory. At what angle of elevation should the gun be to hit the target?

Question: It was calculated that a shell when fired from a gun with a certain velocity and at an angle of elevation 5π 36 rad should strike a given target. In actual practice, it was found that a hill just prevented the trajectory. At what angle of elevation should the gun be to hit the target?