The tangram is an ancient Chinese game that has spread to Europe at the beginning of the '800s and still continues to amuse and intrigue, even for its applications in geometry. The tangram consists of a 7-part (tan) square, such that the angles of them have multiple amplitudes of 45 ° (half of a right angle).
The figures that make up the tangram are 7:
-5 triangles of different sizes: 2 large congruents, 1 medium, 2 small congruents, 
- a square 
- a parallelogram.
We copied the tangram onto a cardboard and then cut out the 7 tan, then reassembled the square and made other polygons and various fancy figures. All figures are equivalent because they are equitable.This game has favored concentration and is an excellent mathematical exercise for the understanding of figures and space. We have answered the following questions and tasks: 

1. What is the width of the corners of the 7 tan?

2. Calculate the area of ​​the 7 tan by taking the square-shaped tan area as the unit of measurement. 

3. Take the side of the square-shaped tan as the unit of measurement and find the length of the sides of the other 6 tan. 

4. What is the area of ​​each of the polygons that can be built with the tangram?