The correct answer is C; 56.5 ft^2
Step-by-step explanation: A careful observation shows that we have three (3) circles in the diagram. One big circle with two smaller circles inserted inside it.
One of the smaller circles has a radius of 3 ft. However note that the tiny strokes on the radii of both circles indicates that they are equal in measurement. Hence, both smaller circles each have a radius of 3 ft. Also, if we extend the radii of both smaller circles from end to end, what we would have is 3 + 3 + 3 + 3 and that equals 12. This is the diameter of the bigger circle. This gives the radius of the bigger circle as 6 ft (diameter/2).
At this point we can begin our calculations. The area of each smaller circle is given as
Area = pi x radius^2
(Please note that ^2 means squared, or raised to the power of 2)
Area = 3.14 x 3^2
Area = 3.14 x 9
Area = 28.26
Remember that we have two smaller circles with equal radius (3 ft)
Hence the area of both circles equals
28.26 x 2 and that equals 56.52 ft
In order to calculate the area of the bigger circle
Area = pi x radius^2
Area = 3.14 x 6^2
Area = 3.14 x 36
Area = 113.04
If the area of the entire larger circle is now known, we can subtract the area of the two smaller circles to help us arrive at the area of the shaded region. This can be expressed as;
Area of shaded region = 113.04 - 56.52
Area of shaded region = 56.52 and approximately this is equal to 56.5 ft