SOLUTION: If the radius of a circle is decreased by 40% , by what percent is the area decreased ?

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Question 233194: If the radius of a circle is decreased by 40% , by what percent is the area decreased ?
Answer by Alan3354(69443) About Me  (Show Source):
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If the radius of a circle is decreased by 40% , by what percent is the area decreased ?
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Area is a function of the square of the radius.
If r2 = 0.6r1, then
Area2 = Area1*(0.6)^2
Area2 = 0.36Area1
That's a decrease of 64%