1. As shown in Figure 1, quadrilateral $ABCD$ is a square with a side length of 4, and there are 3 quartiles on each side. Choose any one of the quartiles on each side of the square, and connect them in sequence to form a quadrilateral.
Ask: What values can the area of such a quadrilateral take?
Please list these values, no proof is required.
1. To calculate the area of a quadrilateral, one can first calculate the areas of the four surrounding right-angled triangles, and then subtract them from the area of the larger square. The possible values for the area sought are $6, 7, 7.5, 8, 8.5, 9, 10$.