2.  There are 3 ways to show two triangles are similar to each other. Those 3 ways are: 1. Angle-Angle Similarity Postulate. (AA~) 2. Side-Angle-Side Similarity Theorem. (SAS~) 3. Side-Side-Side Similarity Theorem. (SSS~)

3. PostulateIf Then If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.

4. TheoremIf Then If an angle of one triangle is congruent to an angle of a second triangle, and the sides that include the two angles are proportional, then the triangles are similar.

5. TheoremIf Then If corresponding sides of two triangles are proportional, then the triangles are similar.

6.  Are the two triangles similar, how do you know? 31° 59° Find the 3 rd angle in one of the triangles to see if it is congruent to the other triangle. The two triangles are similar by the AA~ postulate.

7.  Are the two triangles similar, how do you know? Find the corresponding sides and set up an extended proportion. The two triangles are similar by the SSS~ theorem. 10 8 6 9 12 15

8.  Are the two triangles similar, how do you know? Both triangles share angle M, so check the ratios of the sides that include angle M. The two triangles are Similar by the SAS~ theorem. 8 2 123

9.  P. 455 #’s 7-12, 15-20, 23-26, 37-44