The earliest record of the 7 geometric pieces known as the famous Tangrams occur in a book from China.  It is thought to have originated much earlier, but not studied.  The puzzle is believed to be named after the T'ang Dynasty though some prefer to think it was because of the Tanka opium dealers. Tangrams became popular in Europe and the United States when China reopened up
trade with foreign countries.  In 1942 Fu Tsiang Wang and Chuan-chin Hsiung proved that there are only thirteen different Tangram silhouettes that can occur in which the edges have no indentations.  A diagram of how to make your own pieces can be found at http://www.geocities.com/TimesSquare/Arcade/1335/makeset.htm

Author: Eric Libicki

References:
http://www.geocities.com/TimesSquare/Arcade/1335/tanhist.htm

http://www.uconect.net/~advreason/tanhist.htm