How to play tangram

Fit all seven pieces inside the outline, flat, with no gaps and no overlaps. Prefer to learn by doing? The interactive tutorial walks you through your first puzzle.

Golden rules

Biggest pieces first. They cover the most ground and have the fewest places they can go.
Work in from the edges. Fill corners and edges before the middle. A piece in a corner usually only fits one way.
Look at the gap, not the piece. The shape of the space left over tells you which piece goes there next.
Undo the last piece if you get stuck. If nothing fits the space you just made, that piece is in the wrong place.

What a puzzle actually gives you

A tangram puzzle is a solid shape with no lines inside it. It never tells you where one piece ends and the next begins: that is the puzzle. Here is the sailboat as you get it, and as it turns out to be made.

What you see.

What it is.

Three things you can do to a piece

Move it. Drag a piece from the tray onto the shape. Corners snap to nearby corners, so pieces click together rather than needing to be placed to the pixel.
Turn it. Forty-five degrees at a time, which is all any tangram ever needs.
Turn it over. For most pieces this does nothing turning could not. But some, like the parallelogram, become a different shape.

As it comes straight out of the tray

Turned 45° same piece, leaning the same way

Turned over leans the other way; no rotation gets you here

The sailboat, solved step by step

1Large triangle, down the mast
The biggest piece has the fewest places to go. Its long edge matches the sail exactly.
2The other one, along the boom
The second one meets the first edge to edge, and the sail is done.
3Medium triangle, into the left point
The hull ends in a narrow point. Of the pieces that fit there, this is the biggest.
4Rhomboid, into the right point
The other end is a mirror of the first. The rhomboid only fits once it is turned over.
5Square, flat on the deck
The square needs a right angle, and there is just one spot left with room for it.
6Small triangle, alongside the medium
Small triangles fit almost anywhere, so save them for last and let the gaps decide.
7Small triangle, and the boat is done
The last piece has one place left, which shows the others were right.

The move that looks right and is not

A piece can look right and still be wrong. If nothing fits the gap it leaves, take it out and try another spot. Here the medium triangle fits neatly in the top-left corner of the square, yet it makes the puzzle impossible.

The wrong corner. Nothing left can fill the marked space.

The right corner. Same piece, other end. Now every piece has a place.

What fits in a corner

The pieces only have angles of 45, 90 and 135 degrees, so those are the only corners any tangram figure can have. That turns every corner of an outline from a guess into a short list.

45°, a sharp point. The tip of any triangle, or the sharp end of the rhomboid. Nothing else is that narrow.

90°, a square corner. The right angle of any triangle, or a corner of the small square.

135°, a blunt corner. The rhomboid is the only piece with one, so it is either the rhomboid or two pieces meeting along an edge.

The controls

Tap a piece to turn it 45°.
Tap it twice and that flips the parallelogram, half-turns the rest.
The buttons under the board do the same to whichever piece you touched last.

A / D turn it 45° either way. Double-clicking it, or scrolling over it, turns it too.
F flips the parallelogram, half-turns the rest.
Q sends it back to the tray.
H gives a hint, 3 a puzzle.
R resets the board.
Space pauses the clock.

Now solve one yourself

Play the tutorial →

After that, the daily tangram sets one figure a day, the same one for everybody, against the clock. The shape library holds every silhouette, in both piece sets, and is always open, with three hints per puzzle when a shape will not give. The background page covers where the puzzle came from and how the seven pieces relate to one another, and the printable PDFs put the pieces and the shapes on paper.