Abstract: A ball comprising a plurality of interwoven rings, preferably each of generally polygonal shape.

Abstract: A ball comprising a plurality of interwoven rings, preferably each of generally polygonal shape.

Abstract: A hand toy for improving the fine motor skills of a young child includes a central hub having a plurality of angled openings passing therethrough such that the openings do not intersect one another. The hand toy further includes a plurality of elongate rods each respectively slidably received within one of the openings in the central hub. The terminal ends of the rods extend outwardly from the hub and the rods are slidably movable relative to the central hub without noticeable friction. Each end of the rods has an enlarged stopper element mounted thereon to limit the sliding movement of the rods relative to the hub to prevent the rods from becoming disassembled from the hub during use. The hand toy still further includes a plurality of differently shaped and differently colored ring members which are received on the rods and slidably movable between the central hub and the stopper element at the respective end of the rod.

Abstract: A device and method for illustrating geometric shapes are disclosed which enables individuals to study and visualize the interrelation between geometric shapes and more particularly complementary geometric shapes such as tetrahedrons. The apparatus includes a plurality of tubes that pass through a central support member. Cords pass through the tubes, each cord having its ends connected, forming a closed loop. The tubes are movable within the support member. As the tubes are manipulated, the size and geometry of the visualized shapes are altered. In one embodiment, four tubes and three cords define two complementary tetrahedrons. When the tubes are manipulated to expand one tetrahedron, the complementary tetrahedron shrinks.