Question

You resize a picture so that the radius of the midday Sun appears

four times larger. How much larger does the circumference of the
Sun appear? Explain.
Section 9.1
Circles and Circumference

Answer 1

4 times larger (circumference)

Explanation:

Basically the question is asking:

If radius of a circle becomes 4 times larger, how many times larger is the circumference of the circle?

Let take the original picture radius as "r", so the circumference would be:

`C=2\pi r`

Now, if the radius is 4 times larger, the new radius is "4r", so the circumference would be:

`C=2\pi r\\C = 2 \pi (4r)\\C = 8\pi r`

The number of times it is larger is found by taking the new circumference by original circumference, shown below:

`(8\pi r)/(2\pi r)=(8)/(2)=4`

So, the circumference appears 4 times larger