1. Warm Up (on handout)

2. Hints on Proofs
If two triangles share a side, then you will probably use the ______________ property.
reflexive

3. Hints on Proofs
If you have vertical angles, you will probably use __________ ______ in the proof.
vertical
angles

4. Hints on Proofs
If you are given “midpoint” or “bisects”, then
you WILL use __________________,
_______________________, or
______________________ in the proof.
def. of midpoint
def. of segment bisector
def. of angle bisector

5. Hints on Proofs
If you are given parallel lines, then you will use _______________ _________ angle theorem.
alternate
interior

6. Hints on Proofs
If you are proving parts of a triangle are congruent, then the proof will probably end with ____________.
CPCTC

7. Ways to Prove Triangles are Congruent
Rt. ∆s only
SSS
SAS
ASA
AAS HL

8. Same Side Int. Angle Postulate
Linear Pair is Supplementary
Corresponding Angle Theorem
Definition of Supplementary Angles
Alternate Int. Angle Theorem
Perp. Lines form right angles
All right angles are congruent
Converse S-S Int. Angle Postulate
Def. of a right angle
Converse Corresponding Angle Theorem
Converse Alternate Int. Angle Theorem
Vertical Angles are congruent
Def. of a perpendicular bisector
ASA
Def. of a midpoint
SAS
Def. of Segment Bisector
SSS
Def. of Angle Bisector
AAS HL
Substitution
CPCTC
Reflexive
Symmetric
Third angle theorem
Transitive

9. Steps to Proving :
Mark the picture with :
Decide if your triangles are congruent by: ____, _____, _____, _____, or _____
(write this down by the picture so you don’t forget – this will be your last step or your second to last step)
If you mark it in the picture, you need to mention it in the proof
4. Must have 3 ≅ statements before saying the triangles are ≅ (one for each A or S)
**The givens will either directly give you the ≅, or will help you get one

10. 1.
Statements
Reasons

11. 2.
Statements
Reasons

12. 3.
Statements
Reasons

13. 4.
Statements
Reasons