1. Angle-Angle (AA) Similarity Postulate If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.

2. Prove that the two triangles similar. 45 0 V S R W B 1. 2. 3. 1. 2. 3.

3. Side Side Side Similarity Theorem If the corresponding side lengths of 2 triangles are proportional, then the triangles are similar

4. To prove 2 triangles similar using SSS In order to prove similarity using SSS, you must check each possible proportion of the side lengths of a triangle. Not similar

5. Use SSS to find the Scale Factor and determine whether the triangles are similar…if they are similar name the triangles correctly ∆ ABC ~ ∆ DEF

6. Use SSS to find the Scale Factor and determine whether the triangles are similar Not Similar

7. Side Angle Side Similarity Theorem If 2 triangles have a corresponding congruent angle and the sides including that angle are proportional, then the 2 triangles are similar.

8. Are the Triangles similar? How? yes SAS Name the corresponding Side, Angle, and Side for each triangle

9. Are the Triangles similar? How? yes SAS Name the corresponding Side, Angle, and Side for each triangle Find the scale factor to back it up

10. Are the Triangles similar? How? yes SAS or SSS Name the corresponding Side, Angle, and Side and Side, Side, Side for each triangle. Find the scale factor to back it up

11. Find the Scale Factor and determine whether the triangles are similar using SAS ∆ RST ~ ∆ XYZ

12. Is there enough information to determine whether the triangles are similar? yes Which Similarity Postulate allows us to say yes? SAS

13. Are the triangles similar? Which similarity postulate allows us to say it is similar? yes SAS The sides are proportional and the included angles are congruent.