# Algebra

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The area of a circle is given by the formula A = pi*r^2 and the circumference of the circle is given by C = 2*pi*r. Find the ratio of the area to the circumference. What happens to this ratio if the radius is quadrupled?

Thank you!

• Algebra -

A/C = pi(r^2)/(2pi r)
= r/2

A = pi(4r)^2 = 16pi(r^2)
C = 2pi(4r) = 8pi r

ratio A/C = 16pi r^2/(8pi r) = 2r

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