Polyiamonds are formed by joining unit equilateral triangles to form larger pieces. The name derives from a corruption of the word diamond, which is formed from two triangles; di- being the Greek prefix meaning two.
Moniamond - 1 (1 tile)
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Diamond - 1 (2 tiles)
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Triamond - 1 (3 tiles)
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Tetriamonds - 3 (12 tiles)
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| 1 | 2 | 3 |
Pentiamonds - 4 (20 tiles)
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| 1 | 2 | 3 | 4 |
Hexiamonds - 12 (72 tiles)
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| 1 | 2 | 3 | 4 | 5 | 6 |
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| 7 | 8 | 9 | 10 | 11 | 12 |
For higher orders of polyiamond, the number of pieces is as follows:
Heptiamonds - 24
Octiamonds - 66
Enneiamonds - 160
Dekiamonds - 448