Question 81
Pedrinho has several pieces of wood in the form of a right triangle of legs $1~\mathrm{cm}$ and $2~\mathrm{cm}$. With 4 of these pieces, he manages to assemble a square of side $2~\mathrm{cm}$, as in the figure below. 
Playing with more pieces, he managed to assemble a square using exactly 20 pieces. Assemble you too a square using 20 pieces. (Tip: Calculate the area of the triangles, and thereby calculate the side of the square. Then compare with the hypotenuse of the pieces.)
Playing with more pieces, he managed to assemble a square using exactly 20 pieces. Assemble you too a square using 20 pieces. (Tip: Calculate the area of the triangles, and thereby calculate the side of the square. Then compare with the hypotenuse of the pieces.)