Daily Tangram
The rule
Fill today's shape with all seven tans. Every piece is used, none overlap, and nothing sticks out.
Pick a tan, press Turn until it looks right, then tap the shape to drop it in. It lands wherever it fits around the part you tapped. Tap a tan already down to take it out again.
Where to start
Start with the two large triangles. They take half the shape between them, so once they are placed the rest has far fewer homes. Corners are the next best thing to look at: a sharp point can usually only be the tip of a triangle, and a right angle in the outline is often a corner of the square.
The rhomboid is the one to watch. It is the only piece with no mirror symmetry, so if a shape refuses to close up, that is often what is the wrong way round.
In your hands
Tangram is the oldest puzzle of this kind still played. For the same idea in wood, with pieces that interlock rather than lie flat, see the Fish Tank and the rest of the 2D packing puzzles.
Every Shape Can Be Made
Each shape is built by laying all seven tans down touching one another, and the silhouette is simply their outline. So the arrangement exists before the puzzle does and nothing here is impossible, even on the days it looks it.
The awkward part of tangram on a screen is that the pieces sit at forty five degrees as often as ninety, which no ordinary grid can hold. Here every square of the board is cut into four triangles by its diagonals, and each tan is then an exact set of those, so fitting and overlapping become counting rather than geometry. The way to know that is right is the oldest fact about this puzzle: the seven pieces must tile the square they were cut from. They do.
More to Play
There are twenty four daily sudoku variants, a pentomino board, a sokoban and a hex a hop.
Small enough to live on a desk and be picked up whenever a few minutes go spare. See the 3 Piece Cross, or the rest of the collection.
Frequently Asked Questions
How do you play Tangram?
Fill today's shape with all seven tans. Every piece is used, none overlap, and nothing sticks out.
Is Tangram free to play?
Yes. There is a new tangram here every day, free, with no account and nothing to install. It plays in the browser on a phone or a computer, and it remembers where you got to.
Can every puzzle be solved?
Yes. Each shape is made by laying all seven tans down touching one another, and the silhouette is simply their outline, so the arrangement exists before the puzzle does.