Square: Five isosceles right triangles (two small triangles, one middle triangle and two large triangles, one square and one parallelogram). The two largest triangles are adjacent to each other at right angles, forming a large isosceles triangle. The trapezoidal block and the two smallest triangular blocks are placed in a straight line next to the longest side of the isosceles triangle, and the remaining medium-sized triangular blocks are placed in the lower left corner.

tangram

It is an ancient traditional intellectual toy in China. As the name implies, it consists of seven boards. These seven boards can be combined into many figures, such as triangles, parallelograms and irregular polygons. Players can also combine them into various figures, images, animals, bridges, houses, towers and so on. And some Chinese and English letters.

Tangram was invented by the working people in ancient China, and its history can be traced back to at least the first century BC, and it was basically finalized in the Ming Dynasty. Ming and Qing Dynasties were widely circulated among the people in China. Qing people wrote in Volume I of Cold Records Miscellaneous Knowledge: There are seven ingenious pictures with five shapes and seven numbers recently, and there are thousands of changes.