1. 1Geometry Lesson: Partition and Substitution Postulates Aim: 1) Solve the linear system for x and y. ABCD a) x b) AB, BC, CD What are the Substitution and Partition Postulates? Do Now:

2. 2Geometry Lesson: Partition and Substitution Postulates Partition Postulate: “A whole is equal to the sum of its parts.” Ex: WCMQ Partition Postulate Or, Ex: 1 2 3 D C B A E Partition Postulate

3. 3Geometry Lesson: Partition and Substitution Postulates Substitution Postulate: “A quantity may be substituted for its equal in any expression.” Ex: AB M L K Given Substitution Post. Ex: 1 2 3 D C B A E 4 F Partition Post. Given Substitution Post. Partition Post.

4. 4Geometry Lesson: Partition and Substitution Postulates Example 1: A B C DE Given: Prove: StatementsReasons 1) 2) 3) Given Partition Postulate Substitution Postulate

5. 5Geometry Lesson: Partition and Substitution Postulates Example 2: Given: Prove: StatementsReasons 1) 2) 3) 4) Given Partition Postulate Substitution Postulate AB C D E Def. congruent angles

6. 6Geometry Lesson: Partition and Substitution Postulates Example 3: StatementsReasons 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) Given Def. Rt. angle Partition Post. Given: Prove: A C B E F G DH Partition Post. Subst. Post. Def. Rt. angle

7. 7Geometry Lesson: Partition and Substitution Postulates Example 4, 5: 4) Given: Prove: A C B D 5) Given: Prove: a b c