Since the figures are scaled by a single factor, the scale factor can be gotten by simply finding the ratio of the corresponding sides.
Using the vertical height of the shape, we have the ratio to be
[tex]20\colon12[/tex]Simplifying by dividing through by 4, we have the simplified ratio to be
[tex]5\colon3[/tex]We can confirm by checking the ratio of one side of the base of the shape as follows:
[tex]35\colon21[/tex]Simplifying by dividing through by 7, we have the simplified ratio to be
[tex]5\colon3[/tex]Therefore, the scale factor is 5:3.
