To be able to get the scale factor of the given figures, let's first get the measures of each of their sides and get the ratio of any of the corresponding sides. Let's select the shortest side of the two figures.
We get,
Figure 1: (Black Figure)
Measure of the shortest side: 1 Unit
Figure 2: (Blue Figure)
Measure of the shortest side: 3 Units
Let's now determine the scale factor:
Therefore, the scale factor is 3.