Tangram

What is Tangram?

Tangram is the Chinese puzzle of seven pieces cut from one square: two large right triangles, one medium, two small, a square and a parallelogram. In China it is called qiqiaoban, "the seven boards of skill". The first books of tangram figures were printed there in the early nineteenth century, and around 1817 the puzzle crossed to Europe and America and became a craze, with books of hundreds of silhouettes to rebuild.

The rule is always the same: use all seven pieces, lay them flat, never put one on top of another, and cover the silhouette exactly. The pieces fit together in a surprising number of ways. In 1942 the mathematicians Fu Traing Wang and Chuan-Chih Hsiung proved that exactly thirteen convex shapes can be made from them, and several of those thirteen are among the figures here.

This game holds more than sixty silhouettes: geometric shapes, letters, everyday things, boats, animals and people. Every one comes with a known solution, so every figure can be built, and any other way of covering it exactly counts too. A new figure arrives every day, the same for everyone.

How to play

Cover the dark silhouette with all seven pieces, none overlapping.

• Drag a piece out of the tray onto the board. Let go and it snaps to the nearest corner of the silhouette or of another piece, so pieces meet edge to edge without fiddling.
• Tap a piece to turn it an eighth of a turn clockwise. Eight taps bring it back round.
• Flip mirrors the parallelogram, the only piece that looks different the other way round. The triangles and the square need no flip.
• Back to the tray. Drop a piece on the tray to take it off the board.
• On a keyboard, move to a piece with Tab: the arrow keys move it, Enter or Space turns it, F flips the parallelogram and Delete sends a piece back to the tray.
• Levels. Easy draws the lines between the pieces inside the silhouette. Medium shows only the silhouette. Hard shows a small picture of the figure in the corner, and you build it at full size anywhere on the board.
• Undo, Clear and Hint. Undo takes back your last move, Clear sends every piece back to the tray. A hint lays one piece where the solution has it, for 30 seconds on your score.
• Score. Your time from the first move, plus 30 seconds for every hint. Lower is better.

Strategy tips

1. Place the large triangles first. They are half of the whole area, and there are usually only one or two places they can go. Find the sharpest or widest corners of the silhouette and try them there.
2. Read the angles. Every corner of a tangram figure is a multiple of 45 degrees. A sharp 45 degree point almost always belongs to a triangle; a square corner can be the square, two triangles, or the corner of a large triangle.
3. Count the area. The small triangles are one unit each, the medium triangle, the square and the parallelogram two each, and the large triangles four each. A part of the silhouette with room for two units can only take the medium triangle, the square, the parallelogram or both small triangles.
4. Keep the parallelogram for last. It is the most awkward piece. When everything else is down, the gap left for it shows which way round it must lie, and Flip turns it over.
5. On hard, start from an edge. Build the longest straight edge of the figure first; once one piece sits right, the others snap to it.

FAQ

Is Tangram free to play?

Yes. Like every game on Play, it runs free in your browser, with no download and no account needed.

Can every figure be solved?

Yes. Every silhouette here was built from the seven pieces, and the game keeps that solution. If you find another way to cover it exactly, it counts just the same.

What does a hint do?

It takes the first piece of the stored solution that is not yet in place and lays it there, moving aside any piece in its way. Each hint adds 30 seconds to your score.

What is the daily figure?

Every day everyone gets the same medium figure, so times compare directly on the daily leaderboard.