From the graph, we get
The length of a side of the green shape or preimage=4.
The length of the similar side of the black shape or image=20.
Now, the scale factor is,
[tex]Scale\text{ factor=}\frac{\text{length of image}}{\text{length of preimage}}=\frac{20}{4}=5[/tex]
Therefore, the scale factor is 5.
