The tangram (literally: ‘seven boards of skill’ is a dissection puzzle consisting of seven flat shapes, called tans, which are put together to form shapes. The objective of the puzzle is to form a specific shape (given only an outline or silhouette) using all seven pieces, which can not overlap. It is reputed to have been invented in China during the Song Dynasty,[1] and then carried over to Europe by trading ships in the early 19th century. It became very popular in Europe for a time then, and then again during World War I. It is one of the most popular dissection puzzles in the world.[2][3] A Chinese psychologist has termed the tangram “the earliest psychological test in the world”, albeit one made for entertainment rather than for analysis Over 6500 different tangram problems have been created from 19th-century texts alone, and the current number is ever-growing.[21] Fu Training Wang and Chuan-Chin Hsiung proved in 1942 that there are only thirteen convex tangram configurations (config segment drawn between any two points on the configuration’s edge always pass through the configuration’s interior, i.e., configurations with no recesses in the outline).[22][23] Pieces Choosing a unit of measurement so that the seven pieces can be assembled to form a square of side one unit and having area one square unit, the seven pieces are: 2 large right triangles 1 medium right triangle 2 small right triangles 1 square 1 parallelogram