Notice that the two triangle-like pieces in the
center could be rotated to fit into the part-circles to their sides (prove
this by adding 270° and 90° to get the full-circle 360°).
Now what you’re dealing with is much simpler: the area of two identical
circles. The area of a circle is Pr
2. So plug in radius 4 for r, and multiply that by 2 for 2 circles,
and the answer is 32P (D).