Math CentralQuandaries & Queries


Question from maddy, a student:

Find the exact area of the region bounded by two concentric circles with radii 10 inches and 6 inches.

Hi Maddy,

The area of a circle of radius r inches is π r2 square inches. Concentric circles have the same centre.


What is the area of a circle of radius 10 inches?
What is the area of a circle of radius 6 inches?
The region bounded by the two circles is the region between them, the orange region in the diagram above. What is its area?


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