How do you play Tangram?
Tangram is a puzzle where you use all seven pieces, two large triangles, one medium triangle, two small triangles, a square and a parallelogram, to fill a shadow shape exactly. Pieces may not overlap or stick out past the shadow.
This game has 44 pictures, from simple shapes like a square and an arrow to animals such as a cat, a swan and a camel, people dancing or kicking a ball, and objects like a sailboat, a teapot and a key. Every puzzle was built from a real arrangement of the seven pieces first, so every one can be solved. Any arrangement that fills the shadow counts, even if it differs from ours.
Where does the name come from?
The puzzle comes from China, where it is called qiqiao ban, the "seven boards of skill". In Korea it is known as chilgyo nori (seven skill play) or jihye pan, the "wisdom board".
It reached Europe and America in the early 19th century and became a craze, and the English name tangram dates from that time. Today it is a common math class tool for building a sense of shape and area.
How big are the seven pieces?
If a small triangle has an area of 1, then a large triangle is 4, and the medium triangle, square and parallelogram are 2 each, for a total of 16. Together the seven pieces make one large square.
| Piece | Count | Area |
|---|---|---|
| Large triangle | 2 | 4 |
| Medium triangle | 1 | 2 |
| Small triangle | 2 | 1 |
| Square | 1 | 2 |
| Parallelogram | 1 | 2 |
Two small triangles can be joined to form the square, the medium triangle or the parallelogram, so counting the area of an empty gap tells you which pieces could fit there.
What counts as solved?
- All seven pieces: a leftover piece means the puzzle is not done.
- No overlaps: pieces may not sit on top of each other.
- Stay inside: nothing may stick out past the shadow.
- Turning and flipping: pieces turn in 45° steps, and the parallelogram can be flipped with the flip button. The other pieces look the same when flipped.
- Checking: the shadow must be more than 99% covered with almost no overlap or spill. A single misplaced piece will not pass.
What are the controls?
Drag a piece to move it and tap it to turn it 45° clockwise. When you let go, the nearest corner clicks onto the grid so pieces line up exactly.
On a computer, right click or use the mouse wheel to turn the other way. With a keyboard, press Tab to pick a piece, arrow keys to move it (hold Shift for small steps), R to turn, Q to turn back, F to flip the parallelogram and H for a hint.
Tips
- Place the two large triangles first. Together they cover half of every shape.
- Look at points and narrow gaps. Heads, ears and tails only fit a few pieces.
- Flip the parallelogram when it will not fit. Turning alone cannot make its mirror image.
- Count the empty area. A gap the size of one small triangle needs a small triangle. Twice that size means the square, the medium triangle or the parallelogram.
- Use a hint when stuck. It places one piece in its correct spot.
In 1942 it was proved that the seven tangram pieces can form exactly 13 convex shapes. Solved puzzles and your best time for each are saved in this browser.