1. Reasoning w/ properties from Algebra Reasoning w/ properties from Algebra

2. Properties of Equality with Segments Reflexive property of equality-Reflexive property of equality- for any AB, AB=AB. Symmetric Prop of equality-Symmetric Prop of equality- if AB=BC, then BC=AB. Transitive Prop of Equality-Transitive Prop of Equality- if AB=BC & BC=CD, then AB=CD.

3. Properties of Equality with Angles Reflexive Prop of Equality-Reflexive Prop of Equality- for any <A, m<A=m<A. Symmetric Prop of Equality-Symmetric Prop of Equality- if m<A=m<B, then m<B=m<A. Transitive Prop of Equality-Transitive Prop of Equality- if m<A=m<B & m<B=m<C, then m<A=m<C.

4. Ex: Write an argument for the statement. If AB=CD, then AC=BD. 1.AB=CD 2.AB+BC=CD+BC* 3.AB+BC=AC CD+BC=BD 4.AC=BD * Just added a BC to each side. 1.Given 2.Addition prop of = 3.Segment + post 4.Substitution prop of = A B C D