1. 1Geometry Lesson: Pairs of Triangles in Proofs Aim: How do we use two pairs of congruent triangles in proofs? Do Now: A D R L B P K M

2. 2Geometry Lesson: Pairs of Triangles in Proofs Proofs using pairs of triangles: 1) Prove one pair of triangles congruent using the given information. 2) Use CPCTC and extra Given’s to prove that another set of triangles is congruent. A D R L B P K M Ex: Given Prove: Given CPCTC Given S.A.S. Postulate

3. 3Geometry Lesson: Pairs of Triangles in Proofs Proofs w/ pairs of triangles D X T G Q S V F 3) Given: Prove: L B P F G E R 2) Given: Prove: R F Q A P 1) Given: Prove:

4. 4Geometry Lesson: Pairs of Triangles in Proofs Proofs w/ pairs of triangles R F Q A P 4) Given: Prove: T J N E Q 5) Given: Prove:

5. 5Geometry Lesson: Pairs of Triangles in Proofs Solution #3 StatementsReasons 1) 2) 3) 4) 5) 6) 7) 8) 9) Given Def. angle bisector C.P.C.T.C Substitution Post. Transitive Post. A.S.A. Post. C.P.C.T.C D X T G Q S V F

6. 6Geometry Lesson: Pairs of Triangles in Proofs Solution #5 StatementsReasons 1) 2) 3) 4) 5) 6) 7) Given N T J E Q Reflexive Postulate S.S.S. Postulate C.P.C.T.C S.A.S. Postulate Reflexive Postulate C.P.C.T.C Given: Prove: