A polyomino is a plane geometric figure formed by joining one or more equal-sized squares edge to edge. It's a generalization of dominoes, which are made of two squares. Key Characteristics: Each square (also called a cell) shares at least one full edge with at least one other square. Polyominoes are considered the same if they can be rotated or reflected to match each other (depending on context—some definitions treat rotations/reflections as distinct). Classification by Number of Squares: Polyominoes are named based on how many squares they contain: Monomino – 1 square Domino – 2 squares Tromino – 3 squares Tetromino – 4 squares (famous from Tetris) Pentomino – 5 squares Hexomino – 6 squares … and so on. Types of Equivalence: Free polyominoes: Considered the same under rotations and reflections. One-sided polyominoes: Considered the same under rotations only. Fixed polyominoes: Each distinct rotation or reflection is treated as a different polyomino. Polyominoes are used in recreational mathematics, puzzles, computer games (like Tetris), and tiling problems.
VERSIONS: Note - The major version means added a single official polyomino, and the minor version means added other things. V1.0: Shared, Added Monomino V1.1: Added Symmetry color keys V1.2: Added Sesquiomino V2.0: Added Domino V3.0: Added Triominoes V4.0: Added Tetrominoes V5.0: Added Pentominoes V5.1: Added Tetromino effects V5.2: Added current version and Hemomino V5.3: Added Sesquidomino ------------------------------------------------------------------------ C2A! #polyomino #tetromino #cell #square
