Question

Circle A has been enlarged to create circle A'. The table below shows the circumference of both circles.
Circumference
Circle
Circumference (inches)
А
7
A
10.5
Based on the information in the table, what scale factor was used to create circle A?
:.67
.: 1.5
:: 73.5
1
2
3
4 5 6
Next

Answer 1

Answer:

Option (2) 1.5

Step-by-step explanation:

Rule for the dilation of an image by a scale factor is,

Scale factor = $\frac{\text{Radius of image circle A'}}{\text{Radius of pre-image A}}=\frac{r'}{r}$

                    = $\frac{(2\pi) r'}{(2\pi) r}$

                    = $\frac{\text{Circumference of image}}{\text{Circumference of pre-image}}$

                    = $\frac{10.5}{7}$

                    = 1.5

Therefore, scale factor was used to create a circle A' = 1.5

Option (2) will be the correct option.