Question

If a circle is enlarged so that it has a new area that is 25 times the original, what factor were the dimensions changed by?

5
25
625
1/5

Answer 1

The original radius was made 5 times larger.

Answer 2

The dimensions were changed by 5.

Explanation:

Let the area of original circle be
`x^(2)`

So area of enlarged circle is
`25x^(2)`

The ratio of area for the original and enlarged circle is 1:25

The ratio of area is the sqauare of the scale factor.

So the scale factor is 1:5

The dimensions were changed by 5 .