Polyominoes (Pentominoes)

Polyominoes (aka Pentominoes) date to antiquity and became popular circa 1907. They were first seriously discussed by Solomon W. Golomb. an American Mathematician and Electrical Engineer in 1953 and were later featured by Arthur C. Clarke in a Science Fiction novel, Imperial Earth, in 1974.

Herewith are presented the 12 unique pieces which comprise ALL of the possible shapes made by combining FIVE squares into a single piece such that each square contacts an adjacent square with the full len