1. Section 4.3 & 4.4: Proving s are Congruent
Goals
Identify  figures and corresponding parts
Prove that 2  are 
Anchors
Identify and/or use properties of congruent and similar polygons
Identify and/or use properties of triangles

2. Side-Side-Side (SSS)  PostulateIf N M P If R Q S
Then
Then we can say:

3. Given: W is the midpoint of QS PQ  TS and PW  TW Prove: PQW  TSW
Statements
Reasons

4. Given: D is the midpoint of AC ABC is isosceles Prove: ABD  CBD
Statements
Reasons

5. Side-Angle-Side (SAS)  PostulateIf P Q S If ) W X Y )
Then
Then we can say:

6. Given: QRS is isosceles RT bisects QRS Prove: QRT  SRT
Statements
Reasons

7. Given: BD and AE bisect each other Prove: ABC  EDC
Statements
Reasons

8. Angle-Side-Angle (ASA)  PostulateIf ) R Q S N M P If
Then
Then we can say:

9. Given: B  N RW bisects BN Prove: BRO  NWO
Statements
Reasons

10. Given: 1  2 CD bisects BCE Prove: BCD  ECD3 4 2
Statements
Reasons

11. Angle-Angle-Side (AAS)  TheoremIf P Q S W X Y ) If
Then
Then we can say:

12. Given: AD ║ EC , B is the mdpt of CD Prove: ABD  EBC
Statements
Reasons

13. Given: AD ║ EC , B is the mdpt of CD Prove: ABD  EBC
Statements
Reasons

14. Why Angle-Angle-Angle (AAA) Doesn’t Work
40
50
40
50

15. Why Side-Side-Angle (SSA) Doesn’t WorkB C ( D F E (

16. Theorem 4.8: Hypotenuse-Leg (HL)  TheoremIf D A If
Then B C E F
Then we can say:

17. Given: RS  QT QRT is isosceles Prove: QRS  TRS
Statements
Reasons