1. 1. Complete the congruence statement. ABC  ____ DFE
Warm – up: 5 minutes
1. Complete the congruence statement.
ABC  ____
DFE A B C F E D
2. If CDE  TUV. mT = 32, and mV = 83, find mD. 65
3. Find the slope of (-2, -5) and (-4, -10).
5/2

2. Review Yesterday we learned about Congruent Triangles.
What does it mean if 2 triangles are congruent?
What VERY IMPORTANT abbreviation did we learn yesterday?
What does it mean?

3. 4.4
SSS and SAS

4. Slash marks: indicate congruence, and angle markings
Slash marks: indicate congruence, and angle markings. You must follow the markings!

5. Alt Int Angles are congruent given parallel lines
Overlapping sides are congruent in each triangle by the REFLEXIVE property
Alt Int Angles are congruent given parallel lines
Vertical Angles are congruent

6. Angles can have different measures!
Side-Side-Side (SSS) Congruence Postulate 4 4 5 5 6 6
All Three sides in one triangle are congruent to all three sides in the other triangle.
Angles can have different measures!

7. Ex 1
Determine if whether the triangles are congruent. If they are, write a congruency statement explaining why they are congruent. R T S Y X Z
ΔRST  ΔYZX by SSS

8. Side-Angle-Side (SAS) Congruence Postulate
Two sides are congruent and the INCLUDED angle.

9. Angle in between two consecutive sidesX Z Y
INCLUDED ANGLE

10. ΔPQS  ΔPRS by SAS Ex 2 P R Q S
Determine if whether the triangles are congruent. If they are, write a congruency statement explaining why they are congruent. P R Q S
ΔPQS  ΔPRS by SAS

11. Ex 3
DFE
UVW
by ____
SSS

12. Not enough Information to Tell
Ex 4
Determine if whether the triangles are congruent. If they are, write a congruency statement explaining why they are congruent. R T S B A C
Not congruent.
Not enough Information to Tell

13. ΔPQR  ΔSTU by SSS Ex 5 P S U Q R T
Determine if whether the triangles are congruent. If they are, write a congruency statement explaining why they are congruent. P S U Q R T
ΔPQR  ΔSTU by SSS

14. Not enough Information to Tell
Ex 6
Determine if whether the triangles are congruent. If they are, write a congruency statement explaining why they are congruent. M P R Q N
Not congruent.
Not enough Information to Tell

16. 4.5
ASA , AAS, AND HL

17. The side between 2 anglesC X Z Y
INCLUDED SIDE

18. Angle-Side-Angle (ASA) Congruence Postulate
Two angles and the INCLUDED side

19. Determine if whether each pair of triangles is congruent by SSS, SAS, ASA, or AAS. If it is not possible to prove that they are congruent, write not possible. B A C E D
Ex 5
ΔABC  ΔEDC by ASA

20. Angle-Angle-Side (AAS) Congruence Postulate
Two Angles and One Side that is NOT included

21. Determine if whether each pair of triangles is congruent by SSS, SAS, ASA, or AAS. If it is not possible to prove that they are congruent, write not possible.
Ex 4 G I H J K
ΔGIH  ΔJIK by AAS

22. Your Only Ways To Prove Triangles Are Congruent
SSS
SAS
ASA
AAS
NO BAD WORDS
Your Only Ways To Prove Triangles Are Congruent

23. Ex 1
DEF
NLM
by ____
ASA

24. Ex 2
What other pair of angles needs to be marked so that the two triangles are congruent by AAS? F D E M L N

25. Ex 3
What other pair of angles needs to be marked so that the two triangles are congruent by ASA? F D E M L N

26. Determine if whether each pair of triangles is congruent by SSS, SAS, ASA, or AAS. If it is not possible to prove that they are congruent, write not possible.
Ex 6 E A C B D
ΔACB  ΔECD by SAS

27. Determine if whether each pair of triangles is congruent by SSS, SAS, ASA, or AAS. If it is not possible to prove that they are congruent, write not possible.
Ex 7 J K L M
ΔJMK  ΔLKM by SAS or ASA

28. Determine if whether each pair of triangles is congruent by SSS, SAS, ASA, or AAS. If it is not possible to prove that they are congruent, write not possible.
Ex 8 J T L K V U
Not possible

29. WORK
workbook

30. PRACTICE
Worksheet
Proofs