T Puzzle

Drag the four pieces of the T puzzle onto the outline to make the shape. Turn the pieces so that they fit together exactly, with no gaps and no overlaps.

Drag the four pieces onto the grey outline. Click or tap a piece to select it, then use the Turn left and Turn right buttons to rotate it through 45° (or double-click the piece). The Flip over button turns the selected piece over. When the outline is covered exactly, with no gaps and no overlaps, the Claim Your Trophy button will appear.

Keyboard users can press Tab to move between the pieces, the arrow keys to nudge the selected piece, R to turn it and F to flip it over.

As you make each shape you could take a screen grab (use the Snipping Tool in Windows or take a screen shot if using an iPad or similar) to keep a record of your findings.

The T puzzle first appeared around 1900, when it was often given away as an advertising novelty. This is the asymmetric T version, though there are other versions with slightly different measurements.

In this version the four pieces start off arranged to make the letter T, but originally that was the puzzle: to make the letter T from the four jumbled pieces.

As there are only four pieces you might think that making the T is very simple. However studies have shown that few people are able to solve it in under five minutes, with most people needing more than half an hour. Many people assume that the puzzle is impossible to solve.

The main difficulty in making the T is overcoming the instinct to put the pentagonal piece either horizontally or vertically and, related to this, the tendency to try to fill up the notch of the pentagon. In one study participants were found to spend over 60% of their attempts on such misguided placements of the pentagonal piece.

Have you tried the Tangram Template or Tangram Table activities yet?

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