Tangram is based on furniture sets called 'Yanjitu' in China, which was made during the time of the Song Dynasty.
This furniture consists of six parts. Then a seventh piece of triangular shape is added and these seven pieces are brought together when needed to form a large square table.
During the Ming Dynasty, various versions of these furniture were produced, and then play sets of small pieces of wood started to produced.
Tangram is produced by using the remaining materials from furniture production.