1. Proving Triangles Congruent STUDENTS WILL BE ABLE TO… PROVE TRIANGLES CONGRUENT WITH A TWO COLUMN PROOF USE CPCTC TO DRAW CONCLUSIONS ABOUT CONGRUENT TRIANGLES

2. Two-Column Proof  Displays steps that prove a statement true  Statements on left; Reasons/justifications on right  Need to be specific and display a logical order of your thought process GIVEN: (what you know) PROVE: (what you must show) Statements:Reasons: 1. 2. 3..

3. Acceptable Justifications:  Given statements (usually the first justifications in a proof; need to list the info given to you)  Theorems and postulates (Examples: Vertical Angles are congruent; When lines are parallel, alternate interior angles are congruent; SAS; SSS; etc.)  Definitions (Examples: Definition of a right angle, definition of perpendicular lines, definition of an angle bisector, etc.)  Properties (Examples: Reflexive property, transitive property, substitution property, etc.)

4. CPCTC Corresponding Parts of Congruent Triangles are Congruent Once you know 2 triangles are congruent, you can make conclusions about the other parts of the triangle

5. To use CPCTC in a Proof:

6. Given: ; ; Prove Statements:Reasons: 1. 2. 3. 4. 5. M P J K N L