Hypocycloid prove that an epicycloid with "k" cusps moves snugly inside one with "k"+1 cusps. The evolute of a hypocycloid is an enlarged version of the hypocycloid itself, while the involute of a hypocycloid is a reduced copy of itself. The pedal of a hypocycloid with pole at the center of the hypocycloid is a rose curve. The isoptic of a hypocycloid is a hypocycloid. Curves similar to hypocyloids can be drawn with the Spirograph toy. Specifically, the Spirograph can draw hypotrochoids and epitrochoids. The Pittsburgh Steelers' logo, which is based on the Steelmark, includes three astroids (hypocycloids of four cusps).
Fisher-Price Fisher-Price Fisher-Price is an American company that produces educational toys for children and infants, headquartered in East Aurora, New York. Fisher-Price has been a subsidiary of Mattel since 1993. Founded in 1930 by Herman Fisher, Irving Price, Price's illustrator-artist wife Margaret Evans Price, and Helen Schelle, the name Fisher-Price was established by combining two of the three names. Fisher worked previously in manufacturing, selling and advertising games for a company in Churchville, New York. Price had retired from a major variety chain store, and Helen Schelle previously operated Penny Walker Toy Shop in Binghamton, New York. Fisher-Price’s fundamental toy-making principles