1. Splash Screen

2. Five-Minute Check (over Lesson 2–7) CCSS Then/Now
Postulate 2.10: Protractor Postulate
Postulate 2.11: Angle Addition Postulate
Example 1: Use the Angle Addition Postulate
Theorems 2.3 and 2.4
Example 2: Real-World Example: Use Supplement or Complement
Theorem 2.5: Properties of Angle Congruence
Proof: Symmetric Property of Congruence
Theorems 2.6 and 2.7
Proof: One Case of the Congruent Supplements Theorem
Example 3: Proofs Using Congruent Comp. or Suppl. Theorems
Theorem 2.8: Vertical Angles Theorem
Example 4: Use Vertical Angles
Theorems 2.9–2.13: Right Angle Theorems
Lesson Menu

3. G.CO.9 Prove theorems about lines and angles. Mathematical Practices
Content Standards
G.CO.9 Prove theorems about lines and angles.
Mathematical Practices
3 Construct viable arguments and critique the reasoning of others.
CCSS

4. You identified and used special pairs of angles.
Write proofs involving supplementary and complementary angles.
Write proofs involving congruent and right angles.
Then/Now

5. Concept

6. Concept

7. Adjacent supplementary angles are also called “Linear Pair.”
Definition Linear Pair:
Adjacent supplementary angles are also called “Linear Pair.”
Non-Adjacent Angles
Supplementary Angles

8. Definition Supplementary:
Adjacent Angles
Non-Adjacent Angles
Supplementary Angles

9. Definition of Complementary:
Adjacent Angles
Non-Adjacent Angles

10. Given:
line AC intersects line BD
Prove:
Statements
Reasons

11. When two lines intersect 2 pairs of vertical angles are formed
Definition Vertical:
When two lines intersect 2 pairs of vertical angles are formed
Vertical angles are non-adjacent angles formed by intersecting lines.

12. Given:
Prove:
Statements
Reasons

13. HOMEWORK
Pgs
#’s 1-4, 6, 7-15,

14. End of the Lesson

15. Concept

16. Concept

17. Concept

18. Concept

19. Concept

22. NOTE: DO NOT USE ANY OF THEOREMS 2.9-2.13 IN PROOFS
HOMEWORK
Prove Theorems
NOTE: DO NOT USE ANY OF THEOREMS IN PROOFS