Mathematics >> Height and Distance

A man standing at a point P is watching the top of a tower, which makes an angle of elevation of 30º with the man’s eye. The man walks some distance towards the tower to watch its top and the angle of the elevation becomes 60º. What is the distance between the base of the tower and the point P?
An observer 1.6 m tall is 20$>\sqrt{3}$> away from a tower. The angle of elevation from his eye to the top of the tower is 30º. The heights of the tower is: