7.4. How to cut a $5 \times 5$ square with straight lines so that the resulting pieces can be used to form 50 equal squares? It is not allowed to leave unused pieces or overlap them.
Solution. First, cut the $5 \times 5$ square into 25 squares of $1 \times 1$, then cut each of the resulting squares along the diagonals into 4 triangles, from which, by attaching the longer sides of two triangles to each other, 2 squares can be formed:

![](https://cdn.mathpix.com/cropped/2024_05_06_a954f424d22e8250b881g-1.jpg?height=200&width=465&top_left_y=2199&top_left_x=1452)