1. WARM UP
On desk

2. ESSENTIAL OBJECTIVES
Measure and Classify Angles, Add Angle Measures

3. VOCABULARY

5. Name the angles in the figure.
Example 1
Name Angles
Name the angles in the figure.
SOLUTION
There are three different angles.
PQS or SQP
SQR or RQS
PQR or RQP
You should not name any of these angles as Q, because all three angles have Q as their vertex. The name Q would not distinguish one angle from the others. 5

6. Name the angles in the figure.
More……..
Name Angles
Name the angles in the figure. 1.
ANSWER
S, RST, or TSR 2.
ANSWER
HMK or KMH; NMK or
KMN; HMN or NMH 3.
ANSWER
GJC or CJG; CJF or
FJC; GJF or FJG

7. Use a protractor to approximate the measure of BAC.
Example 2
Draw your own Angle and measure it.
Use a protractor to approximate the measure of BAC.
SOLUTION 1.
Place the center of the protractor over the vertex point A. 2.
Align the protractor with one side of the angle. 3.
The second side of the angle
crosses the protractor at the 50° mark. So, mBAC = 50°. 7

8. VOCABULARY

9. Types of Angles

10. Types of Angles

11. A is obtuse because its measure is greater than 90°.
Example 3
Classify Angles
Classify each angle. a.
mA = 130° b.
mB = 90° c.
mC = 45°
SOLUTION a.
A is obtuse because its measure is greater than 90°. b.
B is right because its measure is 90°. c.
C is acute because its measure is less than 90°. 11

16. Find the measure of PTM.
Example 4
Add Angle Measures
Find the measure of PTM.
SOLUTION
mPTM = mPTN + mNTM
= 30° + 40°
= 70°
ANSWER
The measure of PTM is 70°. 16

17. Find the measure of ABC. 5. 4.
More ……
Add and Subtract Angle Measures
Find the measure of ABC. 5. 4. 6.

18. Find the measure of ABC.
More……
Add and Subtract Angle Measures
Find the measure of ABC. 4.
ANSWER
80° 5.
ANSWER
130° 6.
ANSWER
75°

19. REVIEW: Daily Quiz 1.5
Measure the length of the segment to the nearest
millimeter. 1.
ANSWER
Check students' work. 2.
ANSWER
Check students' work.
Find the length. 3.
Find AC. 25
ANSWER

20. 4.
Find DE.
Find the length. 7
ANSWER
Are the segments shown in the coordinate plane at the right congruent? 5.
No, JK and LM are not congruent.
ANSWER

21. Hw 1.6A