a) The shaded region is that portion of the rectangle that is not in the circle. You need the formulas for the area of a rectangle and a circle.
Area of rectangle = length*width
Area of circle = (π/4)*diameter²
b) The figure shows the width of the rectangle is 14 ft, the same as the diameter of the circle. The length of the rectangle is shows as 21 ft. The shaded area is the difference ...
Shaded Area = Area of rectangle - Area of circle
Shaded Area = (21 ft)*(14 ft) - (π/4)*(14 ft)²
Evaluating this expression, we have
Shaded Area ≈ 294 ft² - 153.9 ft² = 140.1 ft²
