Geomagic Squares

If there is one size of polyomino that has perennially attracted more interest than others, it is the one composed of five unit squares: the pentominoes. Trial and error will show that there are just twelve different shapes that can be formed with five squares, and all twelve of them are to be found among the sixteen pieces in the square above. The four remaining (blue) pieces are tetrominoes. Hence the title: The Twelve Pentominoes.