1. Angles and Angle Bisectors
Lesson 4-2
Angles and Angle Bisectors

2. Lesson 4-1 Practice Check Your Answers

3. Page 45
For help on how to measure angles with a protractor you can watch the following video.
Stop the video at 2:45.

4. Page 45 A B C D
Part + Part = Whole

5. Page 46 Draw pictures!!! X Y Z P R T D M
Hint: Set up an algebraic expression!! E F G H
(75) + (10x) = (20x – 5)

6. Page 46 Read and highlight the definition for bisector of an angle!!
Draw a picture! M A T H
These are “congruency markers”

7. Page 47
Read through Example A. Try to reason through the 2-column proof. A F M L
Check your equation: 11x + 4 = 12x - 2
Check your equation: 2(4x – 10) = 6x – or ½(6x-2) = 4x - 10
Check your equation: (3x + 7) + (6x + 11) = 90

8. Page 48 Hint: Vertical Angles are __________.
Check your equation: (5x + 68) + 9x = 180
Draw a picture!

9. Page 48
Vertical angles are 

10. Page 48
Draw a picture!

11. 4-2 Practice