notes 1.4
DESCRIPTION
AAP and angle bisectorTRANSCRIPT
Warm Up-9/17/09 #3
• Find the coordinate of the midpoint of AB if the coordinate of A is 7 and the coordinate of B is 201. Draw a diagram for credit!
1.4 Angles
Obj: Use AAP and the definition of angle bisector to find angle measures.
Angle
• Formed by two rays or segments with the same endpoint
• Notation: Side
Side
Vertex
F
G
E
Naming an Angle:
• 1. Use three points– Vertex must be the middle
• 2. Use vertex
• 3. Use a numberSide
Side
Vertex
F
G
E
1
Example 1
• Name each angle in every way possible.
21
B
A
C
D
Classifying Angles• Acute
– measure between 0 and 90• Right
– measure of 90• Obtuse
– Measure between 90 and 180• Straight
– measure of 180Angle
Adjacent Angles
• Angles with a common vertex and a common side, but no common interior points
• Adjacent
Angle Addition PostulateAAP
•mAOB + mBOC = mAOCB
A
O
C
AND….
• mDOE + mEOF = 180
D F
E
O
Congruent Angles• Two angles with equal measures
• Notation: m1 = m2• Or: 1 2
• How to mark the diagram:• More than one pair of angles?
1
2
Angle Bisector
• Ray or segment that divides an angle into two congruent adjacent angles
3030
Example 2
• Segment AL bisects KAT. Find x. • m1 = 7x +3• m2 = 6x + 7
321
S T
K
L
A
Example 3
• m1 = x, m3 = 4x. Find x.
321
S T
K
L
A
Homework…
• Pages 21-22• 1-22, 26, 29, 31, 33 • Written Exercises