I don’t understand this

Step-by-step explanation:

Think of it as two rectangles and one triangle.

The first rectangle is 1.5 * 2.5 = 3.75 square feet.

There is two of these rectangles, so you can do 3.75 *2 = 7.5 square feet.

Finally, the triangle is 1.5 by 1.5, so the area is 1.5 * 1.5 / 2 = 1.125.

To find the total area, add the two together: 7.5 + 1.125 = 8.625 square feet