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26 votes
26 votes
We need to cut a circular piece of cardboard with area 200 square centimeters. What will the radius of the circle be? (Round to the nearest whole number.)

User Janek
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1 Answer

21 votes
21 votes

The area of a circle can be calculated with the following formula:


A=\pi r^2

Where "r" is the radius of the circle.

In this case, you know that the area of the circular piece of cardboard is:


A=200\operatorname{cm}^2

Then, knowing the area, you can substitute it into the formula:


200\operatorname{cm}^2=\pi r^2

Finally, you have to solve for "r" in order to find the radius. Rounded to the nearest Whole number, the radius is:


r\approx8\operatorname{cm}

User Bassem Wissa
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3.3k points