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).
Marble (toy) individual artists such as Josh Simpson. Art marbles are usually around 50mm marble (a size also known as a "toe breaker"), but can vary, depending on the artist and the print. Marble (toy) A marble is a small spherical toy often made from glass, clay, steel, plastic or agate. These balls vary in size. Most commonly, they are about in diameter, but they may range from less than to over , while some art glass marbles for display purposes are over wide. Marbles can be used for a variety of games called marbles. They are often collected, both for nostalgia