1. Do-Now
Is enough information given to prove the following triangles congruent? If so, which postulate is being used? Z A D No
ASA C B E W X Y B A C
AAS F D E

2. Example #1 – SSS – Postulate
Use the SSS Postulate to show the two triangles are congruent. Find the length of each side.
AC = 5
BC = 7
AB =
MO = 5
NO = 7
MN =
∆ABC  ∆MNO

3. Remember Mid-Point of a Line Segment
Cuts the line segment into two EQUAL (congruent) parts

4. Example #2 – SAS – Postulate
Given: N is the midpoint of LW N is the midpoint of SK
Prove: ∆LNS  ∆WNK
Statements
Reasons
1) N is the midpoint of LW N is the midpoint of SK
1) Given
2) Definition of Midpoint 2)
3) Vertical Angles are congruent 3)
∆LNS  ∆WNK 4)
4) SAS Postulate

5. Congruent Triangles – 2 Column ProofsB C D E 1 2
Prove ∆AEB = ∆ DEC. Q P S R
Prove ∆QPR = ∆ PSR.

6. A R G D
Prove ∆ADR = ∆ DRG. A B C D E
Prove ∆ADB = ∆ BCE.

7. A B C D 1 2
Prove ∆ABC = ∆ ADC. S P T Q
Prove ∆SPQ = ∆ TPQ.