Question

If you use a scale factor of 15
to create a circle with radius 18 cm, what is the radius of the original circle you dilated?(1 point)
Responses

180 cm
180 cm

9 m
9 m

3.6 cm
3.6 cm

90 cm

Answer 1

Wrong

Answer 2

To find the radius of the original circle before dilation, you can use the formula:

\[
\text{New Radius} = \text{Scale Factor} \times \text{Original Radius}
\]

In this case, the new radius is 18 cm and the scale factor is 15. We can rearrange the formula to find the original radius:

\[
\text{Original Radius} = \frac{\text{New Radius}}{\text{Scale Factor}} = \frac{18 \text{ cm}}{15}
\]

Calculating this gives:

\[
\text{Original Radius} = \frac{18}{15} = 1.2 \text{ cm}
\]

None of the answer choices provided match this calculation, so let's check if I misinterpreted the question. The answers you provided were:

- 180 cm
- 9 m
- 3.6 cm
- 90 cm

It seems there may have been some confusion. According to the scale factor relationship, if we denote the original radius as R:

\[
18 \text{ cm} = 15 \times R
\]

So,

\[
R = \frac{18 \text{ cm}}{15} = 1.2 \text{ cm}
\]

To summarize, the original radius is 1.2 cm, which unfortunately does not appear in the provided options. Please double-check the options or consider clarifying the question or values given.