1. Section 7-3
Similar Polygons

2. Similar Polygons
Two polygons are similar if their vertices can be paired so that:
Corresponding Angles are congruent.
and
Corresponding Sides are proportional (their lengths have the same ratio.)

3. Similar figures have the same shape, but not necessarily the same size.

4. If polygon ABCDE ~ polygon FGHIJ, then

5. Similarity has some of the same properties as equality and congruence:
Reflexive
Symmetric
Transitive

6. Scale Factor
The ratio of the lengths of two corresponding sides of similar polygons
One convenient way to label vertices of similar polygons is by using A and A´ (read A prime), B and B´, and so on.

7. The ratio of the perimeters of similar figures is the same as the scale factor of the similar figures.