1. Corresponding Parts 4-2D Why are corresponding parts of congruent triangles important? What properties of congruence are used in Geometry?

2. Vocabulary We checked to see if we had corresponding numbers to the Lottery numbers. We looked at the instructions to see where the corresponding part fit.

3. One Step Beyond Given: Prove: B A C DE Statements 1.c. 2. a. 3. b. 4. d. 5. f. 6. e. Reasons 1.Given 2.Given 3.Given 4.Rt angles= 5.SAA 6.Def cong ∆

4. CPCTC C orresponding P arts of C ongruent T riangles are C ongruent. When triangles are proven congruent by SSS, SAS, SAA, or ASA, then all remaining parts are congruent by CPCTC

5. Given: Prove: StatementsReasons 1.Given 2.Given 3.Reflexive 4.SSS 5.CPCTC 6.Alt int angles,lines ll X Y Z W

6. Properties of Congruence Reflexive Property Symmetric Property Transitive Property

7. Try It S T U V 1.In the figure, how can you prove that the triangles are congruent by using the SAS postulate? Which additional pairs of sides and angles could you then prove congruent by using CPCTC?

8. Why are corresponding parts of congruent triangles important? Once triangles are proven congruent, all other parts of the triangle are congruent. What properties of congruence are used in Geometry? Reflexive Property Symmetric Property Transitive Property

9. Assignment Page 277, 1-7