A line segment l of length a cm is rotated about a vertical line L, keeping the line l in one of the following three posion I) l is parallel to L and at a distance of r cm. from L, (II) l is perpendicular to L and its mid point is at a distance r cm, from L, (lII) l and L are in the same plane and is inclined to L an angle 30o with it mid point at a distance r cm from L. Let A1,A2,A3 be the are as so qenerated. If r > (a/2), then