Although the image shows it "standing up," we can describe it as a "flat" tetromino--but not all tetrominoes
are "flat:" some have a height, when sitting flat and squarely on the table, of two units.
Find all the mathematically distinct polyominoes up to five squares at a time: monominoes, dominoes, trominoes, tetrominoes
, and pentominoes.
1995), students try to cover a region with a random sequence of tetrominoes
[ILLUSTRATION FOR FIGURE 3 OMITTED].