tangram
    n 1: a Chinese puzzle consisting of a square divided into seven
         pieces that must be arranged to match particular designs

Tangram \Tan"gram\, n. [Cf. Trangram.]
   A Chinese toy made by cutting a square of thin wood, or other
   suitable material, into seven pieces, as shown in the cut,
   these pieces being capable of combination in various ways, so
   as to form a great number of different figures. It is now
   often used in primary schools as a means of instruction.
   [1913 Webster]