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If you double the length of the radius of a circle, what effect does it have on: the circumference of the circle, and the area of the circle?

Thank you!

User Janco
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2 Answers

3 votes
no effect bc it just gives you the diameter
User Teimurjan
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3 votes
c=2pir

when r is replaced with 2r
cnew=2pi2r
cnew=2(2pir)
cnew=2(c)

it is doubling the original circumference



area
area=pir^2
r to 2r
areanwe=pi(2r)^2
areanew=pi(4r^2)
areanew=4pir^2
areanew=4area
it is 4 times of original area


the result is that the circumference is doubled and area is multiplied by 4
User Chris Ruffalo
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6.3k points