Posted by Cassie on .
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 
Reiny,
A/C = pi(r^2)/(2pi r)
= r/2
if radius is quadrulpled
A = pi(4r)^2 = 16pi(r^2)
C = 2pi(4r) = 8pi r
ratio A/C = 16pi r^2/(8pi r) = 2r