1. 4.6: Use Congruent Triangles

2. Properties of Congruent Triangles What pairs of angles and sides are congruent? B C

3. Using CPCTC:
Once you know that triangles are congruent, you can make conclusions about corresponding sides and angles because Corresponding Parts of Congruent Triangles are Congruent (CPCTC).
Ex.1: Suppose you know that by SAS. Which additional pairs of sides and angles are congruent by CPCTC? A B
D C

4. Example 2: B D A C <ACB <DCB
Tell which triangles you can show are congruent in order to prove the statement. What postulate or theorem would you use?
<ACB <DCB B D A C

5. Example 3: M N P L O <PLM <PNO
Tell which triangles you can show are congruent in order to prove the statement. What postulate or theorem would you use?
<PLM <PNO M N P L O

6. Example 4:
Tell which triangles you can show are congruent in order to prove the statement. What postulate or theorem would you use?
MJ ML K J M L

7. Example 5:
Tell which triangles you can show are congruent in order to prove the statement. What postulate or theorem would you use?
ML ON M N L O

8. Example 6:
Tell which triangles you can show are congruent in order to prove the statement. What postulate or theorem would you use?
BC DA B C A D

9. Example 7
Is enough information given in the figure to show that the given statement is true?
 B C A D E B C

10. Example 8
Is enough information given in the figure to show that the given statement is true?
 A C D A E C B

11. Given: WZ  YZ and X is the midpoint of WY Prove: W  Y
Statements Reasons W

12. Given: QR  SR and PR bisects SRQ Prove: PS  PQ
Statements Reasons S