SOLUTION: If the radius of a circle is reduced by 10 percent, by what percent is the area decreased? ...My anwser is 20 percent.

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Question 728395: If the radius of a circle is reduced by 10 percent, by what percent is the area decreased?
...My anwser is 20 percent.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
If the radius of a circle is reduced by 10 percent, by what percent is the area decreased?
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The radius is decreased to 0.9 of the original
Area is a function of the square of the radius --> Area is decreased to 0.9^2 of the original = 0.81
--> 19% decrease