103. A billiard ball, aimed at a point A on the edge of the cushion of a horizontal billiard table, rolls along a line making 18 degrees with the cushion. If the cushion over hangs so that its edge is 4 cm. above the table and the diameter of the ball is 5 cm. find the distance (measured along the edge of the cushion) between the point A and the point where the ball strikes the cushion.