1. All horizontal and vertical distances between adjacent points are equal to 1. What is the area of the triangle with vertices at the black points?
Answer. 1.

Solution. The area of the triangle can be found, for example, by subtracting from half the area of the square the area of the square and the areas of two right triangles. We get $S=10-4-2-3=1$. The figure can be divided in other ways.

Comment. An answer without justification - 0 points. A partition that allows finding the area but lacks calculations - 2 points. With the correct method of solution, there are calculation errors - deduct 2 points for each error.

![](https://cdn.mathpix.com/cropped/2024_05_06_b7652e97e394771cc983g-1.jpg?height=312&width=380&top_left_y=1563&top_left_x=1592)