1. Some Ways to Prove Triangles Congruent
Section 4-2
Some Ways to Prove Triangles Congruent

2. POSTLATES:

3. SSS Postulate
(Side-Side-Side)
If three sides of one triangle are congruent to three sides of another triangle, then the triangles are congruent.

4. Example: A B C E D F
By SSS Postulate,
ABC  DEF

5. 2. SAS Postulate
(Side-Angle-Side)
If two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle, then the triangles are congruent.

6. Example: B A C D
By SAS Postulate,
ABD  CDB

7. 3. ASA Postulate (Angle-Side-Angle)
If two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the triangles are congruent.

8. Example: A B C E D
By ASA Postulate,
ABC  DEC