The radius of a circle was doubled.express the area of th orginal circle as a ratio of the new one?

Question

The radius of a circle was doubled.express the area of th orginal circle as a ratio of the new one?

Answer 1

area of original circle= pi r^2 =x(let)

area of new circle= pi (2r)^2 = pi 4 r^2

=> area of new circle = 4x

therefore,  area of original circle : area of new circle = x/4x = 1 : 4

or area of aorginal circle= 1/4 times area of new circle

Answer 2

the ratio is 1:4

the area of original circle is pi.r.r

the area of new circle is pi.2r.2r

so the ratio is 1:4

Answer 3

ratio= 1:4

as area of original cirlce=pi r^2

area of new circle= pi (2r)^2

if you divide one by the other u get 1/4

Answer 4

area = pi r^2

area1 =  pi r ^ 2

area2 = pi (2r) ^ 2 = pi 4 r^2

area1/ area2 = (pi r ^ 2) / (pi 4 r^2) = 1/4  or 1:4

Answer 5

Circle 1

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radius = r

A1 = π r ²

Circle 2

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A2 = π (2r)²

A2 = 4 π r²

A1 : A2 = 1 : 4

Answer 6

WHEN THE RADIUS IS DOUBLED,AREA BECOMES 4 TIMES THE ORIGINAL ONE.

THE RATIO IS 1:4.

Answer 7

original:new

1:2

Answer 8

Let r be the original radius. Original area = πr²

If the radius is doubled, then the area of the new circle is =  ÃÂ€(2r)² = 4πr²

So the ratio for area of old circle : new circle = πr² : 4πr² = 1: 4

AJM

  

Answer 9

1:4