1. Ch3.3_SegmentsAndAngles.notebook September 27, 2011
Vocab
Chapter 3.3 Midpoint ­ exactly in the middle of a line segment
Segments and Angles
Bisector ­ splits a line segment or angle into 2 equal parts
400
400
The Angle Bisector Theorem
The Midpoint Theorem
If M is the midpoint of AB, If BX is the bisector of <ABC,
1 1
then AM = AB
2 then m <ABX = m <ABC
2
1
and MB = AB 1
2 and m <XBC = m <ABC
2
A
A M B
X
B
C
Example Example
B is the midpoint of AC. Y is the midpoint of XZ.
Find the length of BC XZ = 36
Solve for h
4x + 8 2x + 12 5h + 1
A B C X Y Z

2. Ch3.3_SegmentsAndAngles.notebook September 27, 2011
Vertical Angles
Solve for x
Vertical angles are
always equal in measure
2
1 4x ­ 8
3
4 9x ­ 3
6x+2
Extra Practice 3.3
1 ­ 17