2. Proving Triangles Congruent
5 Methods

3. Proving Triangles Congruent

4. Proving Triangles Congruent

5. Proving Triangles Congruent

6. Proving Triangles Congruent
This one is a THEOREM!!

7. Proving Triangles Congruent_ H L
This one is a THEOREM!!

8. CAUTION!!
BE CAREFUL!!! NOT ALL combinations S & A will give congruent triangles.

9. AAA
AAA is NOT a method to prove two triangles congruent. It will show two triangles that have the same SHAPE, but NOT necessarily the same SIZE!!

10. SSA (OR ASS)
This is humorously referred to as the Donkey Theorem. It is NOT a valid way to show two triangles are congruent!!

11. 1
LKN  LMN by SAS  Postulate

12. 2
Not Congruent

13. 3
FGH  JKL by SAS  Postulate

14. 4
Reflexive Prop=
YZW  WXY by SSS  Postulate

15. Vertical Angles Theorem5
Vertical Angles Theorem
Not Congruent
But Wait……
OMN  OPQ
by AAS  Theorem

16. 6
XYZ  TVU by SSS  Postulate

17. 7 I T R G E Vertical Angles Theorem Alternate Interior Angles Theorem
ERT  IRG by ASA  Postulate