Pentominoes are flat shapes, or tiles, formed by joining together five unit squares. There are 12 different pentominoes. This set of simple geometrical objects has inspired a variety of puzzles and games, including the addictive pastime known as Tetris. The pentomino Web site, created by students of Belgian math teacher Odette De Meulemeester, provides all sorts of information about pentominoes, along with entertaining, challenging puzzles and a bimonthly competition.
