The document defines similar polygons as polygons where corresponding angles are congruent and corresponding lengths are proportional. It introduces the scale factor as the ratio of lengths of corresponding sides in similar polygons. It states the theorem that if two polygons are similar, then the ratio of their perimeters is equal to the ratio of their corresponding side lengths. Finally, it notes that if two figures are congruent, then they are similar, and if two figures are similar, then the ratio of their corresponding sides is the scale factor.