Do Now  Turn your exit slip (for homework) into the “ES” bin.  Turn in your group map.  List the valid congruence shortcuts.  Determine if these triangles are congruent. Explain.

Announcements  Test corrections from the unit 2 test are due Wednesday.  Benchmark Review sheet is due Wednesday.  Benchmark is Wednesday and will count toward your grade.  The class period with the most proficient/advanced scores earns an ice cream party.  Auction in class after the Benchmark.  No school next Monday or Tuesday.

Proofs Congruent Triangles

Today’s Objectives  Write a two-column proof.  Find that corresponding parts of congruent triangles are congruent (CPCTC)  Use CPCTC to prove congruence.  Use Problem Solving Skills

Two-Column Proofs  Used to organize reasoning.  Road map from “given” to “prove”  Left column: Statements that logically flow using deductive reasoning.  Right column: Reasons for each statement.  Reasons may include  “given,”  definitions,  properties,  postulates.

Writing a proof Given:  ABC is isosceles and CD bisects the vertex angle. Prove that  ACD ≅  BCD Statements Reasons

Writing a proof Given:  ABC is isosceles and CD bisects the vertex angle. Prove that AD ≅ BD Statements Reasons

Writing a proof Prove that ΔABP ≅ ΔDCP Statements Reasons

Writing a proof Prove that BP ≅ CP Statements Reasons

Practice: Writing a proof Statements Reasons

Today’s Objectives  Write a two-column proof.  Find that corresponding parts of congruent triangles are congruent (CPCTC)  Use CPCTC to prove congruence.  Use Problem Solving Skills

Exit Slip: Writing a proof Prove that ΔATP ≅ ΔMTI Statements Reasons