Download 1.4 Measuring Angles Date:

1.4 Measuring Angles
Date:
Goals:
• Name and classify angles
Angle:
• Find the measure of an angle
How to name:
Diagram:
Example 1: Naming Angles
For each of the following give two names for 1 , then name the sides and vertex.
A.
B.
C.
A
S
A
2
B
1
1
Q
D
1
B
C
R
C
Name:
Name:
Name:
Vertex:
Vertex:
Vertex:
Sides:
Sides:
Sides:
Angle measure:
How to read a protractor:
Angle classifications:
Acute Angle
Right Angle
Obtuse Angle
Straight Angle
Example 2: Classifying an Angle
Classify each angle below based on its measure.
A.
L
B.
A
N
C.
W
F
N
B
C
B
A
Congruent Angles:
Example 3: Using Congruent Angles
Use the diagram to the right to answer the following questions.
A. PMJ  ________
B. If mQHG  115 , then what other angle has the same measure?
C. Name two angles that are marked as congruent.
D. Name two angles you think may be congruent. Explain.
Angle Addition:
A
D
68
B
41
C
Example 4: Using Angle Addition
Find the measure of the specified angle in the diagrams below.
A. Find mACD
B. Find mLNK
C. Find mJKG if mJKH  90
L
A
J
B
M
G
47
56
C
12 x  15 
D
N
4x
K
K
H