1. Objective: To prove and apply theorems about angles Proving Angles Congruent (2-6)

2. Properties of Equality and Congruence A. Addition Property If a = b, then a + c = b + c B. Subtraction Property If a = b, then a c = b c C. Multiplication Property If a = b, then a*c = b*c D. Division Property If a = b, and c ≠ 0, then a/c = b/c E. Reflexive Property of Equality a = a F. Symmetric Property of Equality If a = b, then b = a G. Transitive Property of Equality If a = b and b = c, then a = c H. Substitution Property If a = b, then b can replace a in any Expression I. Distributive Property a(b + c) = ab + ac a(b c) = ab ac J. Reflexive Property of Congruence ∠ A ≅ ∠ A K. Symmetric Property of Congruence If ∠ A ≅ ∠ B, then ∠ B ≅ ∠ A L. Transitive Property of Congruence If ∠ A ≅ ∠ B and ∠ B ≅ ∠ C, then ∠ A ≅ ∠ C

3. First…. Theorem : a conjecture or statement that you prove true.

4. Remember…

6. W.S. Proof 2