Tetratops in the New York Times: "PATENTS
Geodesic Spinning Tops; Church Playhouse; Vacuum for Tiny Toys
By TERESA RIORDAN
When Kurt Przybilla was growing up in International Falls, Minn., he and his three sisters looked forward every summer to the day their father would put up the geodesic jungle gym in their back yard....
When one imagines the centers of the spheres as dots connected by lines, a cluster of four balls describes a tetrahedron, a three-dimensional shape with four triangular faces. Przybilla's tops also come in clusters of six (an octahedron, with eight triangular faces when the imaginary dots are connected), 12 (an icosahedron, with 20 faces) and 13 (a cube octahedron, which despite its extra ball has only 14 faces).
