This is a rectangle plus a semicircle. We're only asked for the area of the semicircle; if they were better question writers they would have included an answer that's the area of the entire shape. Amateurs.
The semicircle has a diameter of 3 feet, so a radius of 1.5 feet and an area of
[tex]\frac 1 2 \pi r^2 = \frac 1 2 \pi (1.5)^2 \approx 3.534[/tex]
First choice. The half in the formula comes from the fact we want the area of a semicircle.
