1. Goal: The learner will use properties of special pairs of angles.
Lesson 2.7 Prove Angle Pair Relationships

2. Vocabulary Review Complementary Angles Supplementary Angles
Linear Pair
Vertical Angles

3. Right Angles Congruence Theorem
All right angles are congruent.
Let’s Prove It!

4. Given:
Prove: 1 2

5. C D B A

6. Congruent Supplements Theorem
If two angles are supplementary to the same angle, then they are congruent. 1 2 3

7. Would the same idea apply to complementary angles?
Congruent complements Theorem: If two angles are complementary to the same angle, then they are congruent.

8. Linear Pair Postulate: If two angles form a linear pair, then they are supplementary.
Is the converse true?

9. Vertical Angles Theorem: vertical angles are congruent.2 3 1 4

10. Application of the Vertical Angles Theorem

11. Application of the Vertical Angles Theorem Only with Algebra
Find y and the measure of the angle. 7y
3x-21
2x + 4
5y+36
Find the value of x.

12. Find x and the measure of the two angles.

13. Getting Closure
What is the relationship between:
Vertical Angles
Supplementary Angles
Complementary Angles
Linear Pair