mekax
WHAT IS THE AREA OF A CIRCLE WITH THE CIRCUMFERENCE OF 31.4CM?



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pottersheep
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Think about it. Whats the formula for circumference?

Lola9
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\[circumference = 2 \pi r\]find r
then \[area = \pi r^2\]

Harkirat
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for finding area we need value of radius ....
circumference = 2πr
Area = πr^2

pottersheep
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31.4CM =2πr
r = 4.99

pottersheep
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Get it? Cuz 31.4CM divided by 2 divided by π gives you r

pottersheep
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Round that number to 5.

pottersheep
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Now plug the new radius into the area formula

pottersheep
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πr2

pottersheep
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π5^2

pottersheep
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= 78.5cm3

robtobey
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pottersheep has just established that:\[\text{area of a circle}=\frac{c^2}{4 \pi }\]