Now imagine a circle with a 3-mile radius to be a hypothetical metropolitan area with relatively little undeveloped land inside. If the radius of this hypothetical metropolitan area is extended to 10 miles, how much land is added to the original developed area? (Note: Use 3.1416 as the value of ð in your formula for the area of your circle. There are 640 acres in a square mile.)

Question

Now imagine a circle with a 3-mile radius to be a hypothetical metropolitan area with relatively little undeveloped land inside.  If the radius of this hypothetical metropolitan area is extended to 10 miles, how much land is added to the original developed area?  (Note:  Use 3.1416 as the value of ð in your formula for the area of your circle.  There are 640 acres in a square mile.)

Reiny · Answer

The original area with a 3 mile radius was 9pi square miles The new area with a 10 mile radius is 100pi square miles So the new area added is 91pi square miles or 91*3.1416*640 = 182,967 acres