Polyominoes are shapes that are made by joining
identical squares along their edges.
A domino is a shape made from two identical squares. The A-piece shown
in the illustration is the only example of the domino.
A tromino is a shape made from three identical squares. There are only
two different trominoes – they are shown as two B-pieces above.
A tetromino is a shape made from four identical squares. Two
tetrominoes shown as C-pieces are really the same. If you cut them out
or paper, they would be exactly the same shape. Two different
tetrominoes are shown as D-pieces in the illustration. How many other
different tetrominoes can you find?
A pentomino is a shape made from five identical squares. Two different
pentominoes are shown in the illustration as the couple of E-pieces.
How many other different pentominoes can you find?