1. Properties of Equality
Addition POE
Subtraction POE
Multiplication POE
Division POE
Reflexive POE
Symmetric POE
Transitive POE
Substitution POE

2. Properties of Congruence
Reflexive property of congruence
Symmetric property of congruence
Transitive property of congruence

3. Helpful tips Use definition only if measure of degree is used
Theorems are mathematical statements proven to be true
Definition states the meaning of a term or idea
Are reversible
Postulates statements are accepted to be true but are not formally proven. We normally use postulates to prove theorems.

4. Theorems If two angles are right angles then they are 
If two angles are straight angles then they are 

5. Statements of Logic ~ means “not “ Conditional statement If p then q
mathematically written p  q
~ means “not “
Negation symbol
Converse Inverse Contrapositive
if q then p if ~p, then ~q if ~q then ~p
In general converse is not necessarily true
If the conditional statement is true then the contrapositive is true

6. Chapter 1 we used Vertical angles are congruent
Linear pair property (adjacent and form a straight angle