1. Splash Screen

2. Five-Minute Check (over Lesson 2–6) CCSS Then/Now
Postulate 2.8: Ruler Postulate
Postulate 2.9: Segment Addition Postulate
Example 1: Use the Segment Addition Postulate
Theorem 2.2: Properties of Segment Congruence
Proof: Transitive Property of Congruence
Example 2: Real-World Example: Proof Using Segment Congruence
Lesson Menu

3. A. Distributive Property B. Addition Property C. Substitution Property
State the property that justifies the statement. 2(LM + NO) = 2LM + 2NO
A. Distributive Property
B. Addition Property
C. Substitution Property
D. Multiplication Property
5-Minute Check 1

4. A. Distributive Property B. Substitution Property C. Addition Property
State the property that justifies the statement. If mR = mS, then mR + mT = mS + mT.
A. Distributive Property
B. Substitution Property
C. Addition Property
D. Transitive Property
5-Minute Check 2

5. A. Multiplication Property B. Division Property
State the property that justifies the statement. If 2PQ = OQ, then PQ =
A. Multiplication Property
B. Division Property
C. Distributive Property
D. Substitution Property
5-Minute Check 3

6. State the property that justifies the statement. mZ = mZ
A. Reflexive Property
B. Symmetric Property
C. Transitive Property
D. Substitution Property
5-Minute Check 4

7. C. Substitution Property D. Transitive Property
State the property that justifies the statement. If BC = CD and CD = EF, then BC = EF.
A. Reflexive Property
B. Symmetric Property
C. Substitution Property
D. Transitive Property
5-Minute Check 5

8. Which statement shows an example of the Symmetric Property?
A. x = x
B. If x = 3, then x + 4 = 7.
C. If x = 3, then 3 = x.
D. If x = 3 and x = y, then y = 3.
5-Minute Check 6

9. G.CO.9 Prove theorems about lines and angles.
Content Standards
G.CO.9 Prove theorems about lines and angles.
G.CO.12 Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.).
Mathematical Practices
2 Reason abstractly and quantitatively.
3 Construct viable arguments and critique the reasoning of others.
CCSS

10. You wrote algebraic and two-column proofs.
Write proofs involving segment addition.
Write proofs involving segment congruence.
Then/Now

11. Reflexive Property
Equality
Congruence

12. I am as tall as myself.

13. Symmetric Property
Equality:
Congruence:

14. If I am as tall as my brother, my brother is as tall as me.

15. Transitive Property
Equality:
Congruence:

16. If I am as tall as my brother, and my brother is as tall as my cousin,
I am as tall as my cousin.

17. REMEMBER 123… RST COMPARING 1 THING is REFLEXIVE
COMPARING 2 THINGS is SYMMETRIC
COMPARING 3 THINGS is TRANSITIVE
1-4 Solving Equations

18. Concept

19. Definition of a Midpoint of a Segment

20. Bisector of a Segment F l G M H

21. Ex. Writing a proof: Given: 2AB = AC Prove: AB = BC A B C 2AB = AC
Copy or draw diagrams and label given info to help develop proofs
Ex. Writing a proof:
Given: 2AB = AC
Prove: AB = BC A B C
Statements
Reasons
2AB = AC
AC = AB + BC
2AB = AB + BC
AB = BC
Given
Seg. Add Pos
Trans. Or subst.
Subtr. Prop.

22. Given:
Prove:
Statements Reasons 1. 2. 3. 4. 5.
Example 2

23. Use the Segment Addition Postulate
Proof:
Statements Reasons
Example 1

24. Given: AC = AB ; AB = BX; CY = XD Prove: AY = BD
Prove the following.
Given: AC = AB ; AB = BX; CY = XD
Prove: AY = BD
Statements Reasons
Example 1

25. HOMEWORK Pg ,2&4

26. End of the Lesson