[" A man observes that when he moves up a distance "c" metres on a slope,the "],[" angle of depression of a point on the horizontal plane from the base of the slope "],[" is "30^(@)," and when he moves up further a distance "c" metres the angle of "],[" depression of that point is "45^(@)" .The angle of inclination of the slope with the "],[" horizontal is "],[" (Man starts from bottom of slope) "]