If a fan-shaped backboard is being used in
(a) and in
(b), the ball remains live. If a rectangular backboard is used in
(a), the ball remains live after touching the side edge, but it is a violation if it passes directly over the backboard. In
(b), the ball remains live if it touches a side edge or the top edge if it rebounds and comes down in front of the backboard. The ball becomes dead if it passes over the top of a rectangular backboard regardless of the action which causes it to pass over or whether it comes from the front or back of the plane.