Problem 5.5. From a $6 \times 6$ grid square, gray triangles have been cut out. What is the area of the remaining figure? The side length of each cell is 1 cm. Give your answer in square centimeters.

![](https://cdn.mathpix.com/cropped/2024_05_06_899cf5197845501d962eg-11.jpg?height=309&width=313&top_left_y=92&top_left_x=566)
Answer: 27.

Solution. The area of the entire square is $6 \cdot 6=36$ sq. cm.

Divide the triangle located in the middle of the square into two smaller triangles, as shown in the picture on the left. Then the dark gray triangles can be combined into a rectangle $1 \times 3$, and the light gray triangles into a rectangle $2 \times 3$. Therefore, the area of the figure that remains after cutting out all the triangles is 36-3-6 $=27$ sq. cm.
![](https://cdn.mathpix.com/cropped/2024_05_06_899cf5197845501d962eg-11.jpg?height=310&width=702&top_left_y=726&top_left_x=369)