Tangram:

"Tangrams are Chinese puzzles. In Chinese Tangram is called Hanyu Pinyin meaning “seven boards of cunning”. While the trangram is often said to be ancient, its existence has only been verified as far back as 1800.

A tangram consists of 7 pieces, called tans, which fit together to form a square. The pieces are:

5 right isosceles triangles
2 small (legs of 1)
1 medium size (legs of √2)
2 large size (legs of 2)
1 square (side of 1)
1 parallelogram (sides of 1 and √2)

The objective is to form a specific shape with seven pieces. The shape has to contain all the pieces, which may not overlap."

From Wikipedia, the free encyclopedia

Visit these websites to play the online version of Tangrams:

http://pbskids.org/sagwa/games/tangrams/ 

http://pbskids.org/cyberchase/games/area/tangram.html 

http://standards.nctm.org/document/eexamples/chap4/4.4/part2.htm 

http://www.apples4theteacher.com/chinese-tangrams.html 

http://cs.bmcc.cc.or.us/mth213/Labs/online%20tangrams.htm 

http://teams.lacoe.edu/documentation/classrooms/amy/geometry/5-6/activities/tangrams/tangrams.html