Tangram

A standard tangram set consists of seven flat pieces called tans: two large right triangles, one medium right triangle, two small right triangles, one square, and one parallelogram. When assembled together, these seven pieces form a single square. The puzzle challenges players to rearrange all seven pieces into target shapes.

The tangram originated in China and was brought to the West in the early 19th century via trade routes. The puzzle became wildly popular in Europe and America during the 1810s and 1820s. The name 'tangram' is believed to derive from the Tang dynasty, though the puzzle itself is much more recent.

The seven tans can be rearranged into thousands of distinct silhouettes, including animals, human figures, letters, and geometric shapes. Classic tangram puzzle books contain hundreds of challenges where all seven pieces must be used without overlap. Some of the most famous target shapes include a cat, a swan, and a running person.

Tangrams are widely used in elementary and middle school math classrooms to teach concepts such as geometric shapes, area, perimeter, fractions, and spatial reasoning. The puzzle helps students develop problem-solving skills by physically manipulating shapes. The fact that the seven pieces can be rearranged into a square of known area makes them useful for demonstrating geometric decomposition.