Soma cubeThe Soma cube is a mathematical puzzle by Piet Hein. Seven pieces made out of unit cubes must be assembled into a 3x3x3 cube. The pieces can also be used to make a variety of other interesting 3d shapes.
The seven soma pieces are all variants on the bent triomino:
- The bent triomino
- T: a row of three blocks with one added below the center
- L: a row of three blocks with one added below the left side
- S: bent triomino with block placed on outside of clockwise side
- Left screw: unit cube placed on top of anticlockwise side. Chiral in 3D.
- Right screw: unit cube placed on top of clockwise side. Chiral in 3D.
- Branch: unit cube placed on bend. Not chiral in 3D.
(Note the lack of a 2x2x1 square and a 4x1x1 line, and addition of a right-angle piece of only 3 blocks. Of course, if the puzzle actually consisted of only, and all, possible 4 block pieces, then it wouldn't be solvable.)