Question

Are the quadrilaterals similar? If so, give the scale factor. If not, explain.

Answer 1

These are not similar.  For them to be similar, they need to exist in proportion to each other for every single side.  The ratio of the 12:9 sides is 4:3 when reduced.  The ratio of the other 2 sides is 5:3.  They all have to have the same ratio for them to be similar.