1. Warm Up
Rewrite each term using math symbols you learned in chapter 1 (symbols for a line, angle, ray, etc.)
Example: MN
Ray MN _________________________________________________________
Angle ABC ___________________________________________
Line segment JK _________________________________________
Congruent ___________________________________________
Length of line segment with endpoints Y and Z _________________

2. Algebraic Reasoning and Proofs (part 2)
Chapter 2.4

3. To recap: A proof is like a story, where the order is VERY important
One type of math proof is a 2-column proof. It has:
Statements on left
Reasons on right
We reviewed Algebraic Properties as “reasons” in math proofs:
Addition property of equality
Subtraction property of equality
Multiplication property of equality
Division property of equality
Substitution property of equality
Distributive property

4. Other Properties of Equality
Reflexive Property of Equality
Reflexive property examples:
BD = BD
x = x
< ABC = < ABC

5. Other Properties of Equality
Symmetric Property of Equality
Symmetric property examples:
If x = y, then y = x

6. Other Properties of Equality
Transitive Property of Equality
Transitive property examples:
If BC = XY and XY = 8,
Then BC = 8

7. Which property?
Copy the statements below. Use the property given to complete each one.
20 + CD
Substitution Property of Equality: If AB = 20, then AB + CD = ___________.
m∠2 = m∠1
Symmetric Property of Equality: If m∠1 = m∠2, then ______________.
m∠1 = m∠3
Transitive Property of Equality: If m∠1 = m∠2 and m∠2 = m∠3, then ____________________________.
m∠ABC
Reflexive Property of Equality: m∠ABC = ________________.

8. Reasons to be used in proofs
Addition Property of Equality (Add Prop. Equality)
Subtraction Prop. Equality
Multiplication Prop. Equality
Division Prop. Equality
Substitution Prop. Equality
Distributive Prop.
Reflexive Property
Symmetric Property
Transitive Property
Definition of complementary angles
Definition of supplementary angles
Definition of angle bisector or segment bisector
Definition of congruent segments or angles
Definition of midpoint