Billy is constructing a garden divided into 8 equal sections. The diameter of the garden is 12 feet. What is the area, in square feet, of one section of the garden?

If the diameter of the garden is 12 ft, then the radius is 6 ft.
The area is then π(6 ft)^2, or 36 ft^2.
Then the area of one of the 8 equal sections of the garden is 36/8 ft^2, or 9/2 ft^2, or 4.5 ft^2.