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| Math Central | Quandaries & Queries |
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Question from Math, a parent: The bull’s eye of a target is a circle 20 cm in diameter. It is surrounded by four rings, each 15 cm wide. Find the area of each ring. |
Hi,
I can help get you started. Here is my diagram of the bull's eye, not to scale.
The outside circle has a radius of $10 + 15 + 15 + 15 + 15 = 70$ cm. What is the area of a circle of radius 70 cm?
The next smaller circle has a radius of $ 10 + 15 + 15 + 15 = 55$ cm. What is the area of a circle of radius 55 cm?
The area of the largest ring, the red ring, is the difference between the two areas you just calculated.
Penny
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