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4.4 - CPCTC. Do Now: Write the converse of the Polygon Congruence Postulate and give an example. Do you think the converse is true?. Agenda. Objective and Preview Quick Review CPCTC Flowchart Proof Practice. Objective and Preview.
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4.4 - CPCTC Do Now: Write the converse of the Polygon Congruence Postulate and give an example. Do you think the converse is true?
Agenda • Objective and Preview • Quick Review • CPCTC • Flowchart Proof • Practice
Objective and Preview • OBJ: Use congruence of triangles to conclude congruence of corresponding parts. • Preview: • CPCTC: Corresponding Parts of Congruent Triangles are Congruent • Flowchart proofs organize thoughts visually
Quick Review 1.) Make a congruence statement: BADC≅ _________ 2.) State the 5 valid tests of triangle congruence
CPCTC 3.) If you have proven ΔABC≅ΔDEF, what six things can you say?(Think back to the “Do Now”) 4.) This idea is often stated asCorresponding Parts of Congruent Triangles are Congruent 5.) It is abbreviated asCPCTC *CPCTC can be used as a justification in proofs*
6.) Example • Prove that opposite angles in a parallelogram are congruent. • How can you prove this using what you know about triangles?
Flowchart Proof • A way to visually organize information • Statements are written in boxes • Justifications are written underneath • Arrows connect boxes that are logically related • Arrow points from one box to a box that follows logically from it
Example pg. 236 in your book
7.) Example • Finish the flowchart proof:
8.) Example Write a flowchart proof: Given: Prove: Start by interpreting the diagram and analyzing the information.
Before you leave… • Summarize your notes • HW: Section 4.4 Part 1 p. 240-241 #18, 20-22, 27-29