7 ESERCIZI Poligoni e aree PRACTICE WITH CLIL Tangram The Tangram is an ancient Chinese game, which was carried over to Europe at the beginning of the XIX century; it consists of seven tesserae which, if arranged like in a puzzle, can form many shapes. The shapes, traditionally made of wood, were originally kept in a square pouch. The figure on the side shows how they can be assembled to form a square. The goal of the Tangram is to put together all the seven pieces on the plane and to represent the shapes shown as examples in the booklet accompanying the game. As in a puzzle, the pieces should be placed side by side and cannot overlap. All the shapes reproduced have therefore equal area. It is your turn to build a Tangram. 1. From a paperboard, cut a square having A, B, C and 3. Thereafter, let us overlap A and D to the centre D as vertices. Fold the paperboard along the four lines of symmetry of the square, so to obtain the foldings referred to hereinafter with coloured lines. A E A D G H point O so to obtain the last two segments EH and EG. E I H G L O B F C D B O F C 2. Now, divide into two equal parts segments AO and 4. If you cut the paperboard along the two foldings OB. To proceed like this, it is sufficient to overlap the AB side of the square paperboard with the folding EF. You will obtain a folding, which passes through points I and L. A H E I C D B A E A E G L B D here indicated, you can obtain a paperboard Tangram. O F C Find the dissection that, starting from the Tangram pieces, will reproduce the following figures. 305