This lesson explains 3 different ways to prove triangles are similar by looking at corresponding angles and sides as well as works out some practice problems. There is Angle-Angle (AA) where if you can prove to triangles have 2 sets of congruent corresponding angles, then you prove the triangles are similar. There is Side-Side-Side (SSS) where if you can prove 3 sets of corresponding sides are proportional, then you can prove the two triangles are similar. Also, there is Side-Angle-Side (SAS) where if you can prove 2 sets of corresponding sides are proportional and the included angles are congruent, then you can prove the triangles are similar. I also solve several practice problems to explain this lesson better.
