Tangrams Game

The objective of the game is to fit the seven different pieces together to form the same shape as the figure on the right. Below is a some background information about Tangrams which you might be interested to read while the applet is loading.

Instructions:

• Click and drag to move a piece.
• Left or right click to rotate a piece by 45 degrees.
  (Click and drag with control pressed rotates a piece freely).
• Shift-click to flip a piece.
• For a possible solution, click on the figure on the right.

Thank you to Angela Chang for providing this tangram applet.

History of Tangrams

In 1903 the great American puzzlist Sam Lloyd produced what he called "The Eighth Book of Tan", which included a spoof history of this intriguing Chinese puzzle. As well as linking each of the first seven imaginary books to various historical figures, he suggested the puzzle was invented 4000 years ago by the god Tan. His book, which also included some 700 Tangram patterns, proved to be a very successful enterprise and generated a substantial profit for the author.

The true history of Tangrams is in fact shrouded in myth and mystery, and the truth of its inventor, origin and etymology are the subject of some considerable speculation.

The earliest known literary reference to Tangrams is in a Chinese book dated 1813, but it is widely accepted that the puzzles were already well established in China by that time.

Perhaps the most plausible of the theories pertaining the etymology of the Tangram is that it may be derived from Tang , the dynasty that ruled China from AD 618-907 (regarded as a golden age of Chinese poetry and art). Other theories include the suggestion that it may have evolved from the now obsolete English word "Tamgram", meaning a puzzle or trinket. It has also been suggested that it could have acquired its name from the Tank people of southern China and Hong-Kong, who, well known for their exporting, might well have first introduced the puzzle to Europe and America, where it has gained in popularity since the nineteenth century when trade routes with China were opened up.

Its introduction to the West lead to the publication of various books and sales of Tangram puzzles of varying quality, ranging from cheap wooden or clay models, to a wide variety of more lavish versions delicately carved from more precious materials such as ivory or jade.

Among those known to have been enchanted by this most intriguing of puzzles are Napoleon Bonapart, Lewis Carroll and Edgar Allen Poe.

In 1942, Fu Tsiang Wang and Chuan-Chin Hsiung proved the existance of a finite set of Tangram patterns; a set of 13 "convex" shapes, where a "convex" shape is defined as one which has no indentations along its outside edge. You might like to try to see how many of these 13 shapes you can find for yourself, either by using the Java Applet above, or by making your own Tangram shapes.

Solution to the 13 "convex" patterns

Tangram Template that you can print and use for making your own Tangram pieces.

Tangram Paradox

Below is the first Tangram pardox, discovered by Sam Loyd and H.F. Dudeney.

Both images use all seven Tangram pieces. Both include exactly the same geometric shape. But one has a foot and one does not. Admittedly, it is not the most profound paradox featured at curiouser.co.uk but viewers might enjoy trying to make these two patterns nevertheless.