SOLUTION: a circle has a radius of 10 inch. Find the increase in area that occurs when the radius is increased by 2 inches. Round to the nearest hundredths?

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Question 170090This question is from textbook
: a circle has a radius of 10 inch. Find the increase in area that occurs when the radius is increased by 2 inches. Round to the nearest hundredths? This question is from textbook

Found 2 solutions by Alan3354, nerdybill:
Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website!
a circle has a radius of 10 inch. Find the increase in area that occurs when the radius is increased by 2 inches. Round to the nearest hundredths?
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At 10": Area = pi*10*10
A = 100*pi
At 12": Area = pi*12*12
A = 144*pi
The increase is 44*pi
44*pi = 138.23 sq inches

Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website!
a circle has a radius of 10 inch. Find the increase in area that occurs when the radius is increased by 2 inches. Round to the nearest hundredths?
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Area of a circle is (pi)r^2
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"area of increased radius circle" - "area of original circle"
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(pi)(10+2)^2 - (pi)(10)^2
(pi)(12)^2 - (pi)(10)^2
pi ((12)^2 - (10)^2)
pi (144 - 100)
pi (44)
(3.14)(44)
138.16 sq inches