50. AMPHITHEATER Suppose a singer is performing at an
amphitheater. We can model this situation with polar
coordinates by assuming that the singer is standing at
the pole and is facing the direction of the polar axis.
The seats can then be described as occupying the area
defined by -45°<0<45° and 30 < r < 240, where r is
measured in feet.
a. Sketch a graph of this region on a polar grid.
b. If each person needs 5 square feet of space, how many
seats can fit in the amphitheater?