Question

How will the circumference of the circle change if it is dilated by a scale factor of 4?
16cm

The circumference will be 4 times greater than the original.
The circumference will be 16 times greater than the original.
The circumference will be 1/4 the original.
The circumference will be 1/16 the original.

Answer 1

The circumference of a circle has the formula:

C = 2 π r

 

Now when it is dilated by a factor of 4, this only means that the radius is also multiplied by a factor of 4, therefore the new circumference is:

C’ = 2 π (4 r)

C’ = 8 π r

So it also grows 4 times.

 

Answer:

The circumference will be 4 times greater than the original.

Answer 2

Answer:

C

Step-by-step explanation:

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