1. 1.4 Measure & Classify Angles
1.4 Measure and Classify Angles
Angle: 2 different rays with same endpoint
Sides Vertex
Naming Angles W
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014
130
140 50
10 170
0 180
20
160
30
150
40
60
120
110
70
100
80
90
90
0°
80
100
70
110
120
60
130
50
140
40
150
30
160
20
170 10
180 0
X
Y
Z
WXY or YXW
YXZ or ZXY
WXZ or ZXW
Measuring Angles
We use protractors to measure an angle
Classifying Angles
Acute: < 90
Right: 90
Obtuse: >90 and <180
Straight: = 180
37
°
90
°
133
°
180
°

2. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014

3. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014

4. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014
Angle Addition Postulate: If P is in the interior of RST, then the
measure of RST is equal to the sum of measures of RSP and PST
m RST = m RSP + m PST
S
T
P
R
m RST
m RSP
m PST

5. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014

6. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014
Congruent Angles: same measure A ≅ B

7. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014

8. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014
Extra Credit Point if you do this on
the board. Please raise your hand!

9. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014

10. 1.4 Measure & Classify Angles
HW pg. 28 #4­26
even, 34­42
even
August 20, 2014
HW
pg. 28
#4-26 even,
34-42 even