Hello!
In this question, we can relate the definition of similar polygons to the side lengths.
If two given polygons are similar, that means that each corresponding side is multiplied by a certain, equivalent ratio to get the side length of the other side.
That means that we can take any side length ratio and set it equal to a ratio including the unknown side length.
[tex]\frac{6}{x}=\frac{2}{1.4}[/tex]
[tex]8.4=2x[/tex]
[tex]x=4.2[/tex]
Hope this helps!
