Polygons
Any two polygons are similar if their corresponding angles are congruent and the measures of their corresponding sides are proportional:
In the figure above the ratio or the scale factor of the quadrilateral to the left versus the quadrilateral to the right is ½. We could also turn it around and say that the scale factor for the quadrilateral to the right to the quadrilateral to the left is 2.
Video lesson
Find the ratio between the two similar figures