1. 7-2 Angles Course 2 Warm Up Warm Up Problem of the Day Problem of the Day Lesson Presentation Lesson Presentation

2. Warm Up Draw each figure. 1. line segment 2. line 3. ray 4. plane Course 2 7-2 Angles

3. Problem of the Day What is the measure of the smaller angle between the hour hand and the minute hand on a clock at eight o’clock? 120° Course 2 7-2 Angles

4. Learn to identify angles and parts of angles. Course 2 7-2 Angles

5. Vocabulary angle vertex right angle acute angle obtuse angle straight angle complementary angles supplementary angles Insert Lesson Title Here Course 2 7-2 Angles

6. Course 2 7-2 Angles An angle is formed by two rays with a common endpoint. The two rays are the sides of the angle. The common endpoint is is the vertex. You can name an angle in three ways: with the capital letter at the vertex: B,B, with the number inside the angle: 1, with three capital letters so that the letter at the vertex is in the middle: ABC or CBA A C B 1 Vertex

7. Course 2 7-2 Angles Angles are measured in degrees (°). You can use a protractor to measure an angle. The measure of XYZ is 122°, or m XYZ = 122°.

8. Give the measurement of each angle. Additional Example 1A & 1B: Identifying Angle Measures Course 2 7-2 Angles A. STV B. XTU m STV = 55° m XTU = 25°

9. Give the measurement of each angle. Additional Example 1C &1D: Identifying Angle Measures Course 2 7-2 Angles C. WTU D. STX m WTU = 40° + 25° m STX = 155° m WTU = 65° m STX = 55° + 60° + 40°

10. Try This: Example 1 Give the measure of each angle. Insert Lesson Title Here Course 2 7-2 Angles A. STV B. XTU m STV = 35° m XTU = 40° 35° 55° 50° 40° S V W X U T

11. Try This: Example 1 Continued Give the measure of each angle. Insert Lesson Title Here Course 2 7-2 Angles C. WTU D. STX m WTU = 50° + 40° m STX = 140° m WTU = 90° m STX = 35° + 55° + 50° 35° 55° 50° 40° S V W X U T

12. Course 2 7-2 Angles An angle’s measure determines the type of angle it is. A right angle is an angle that that measures exactly 90°. The symbol indicates a right angle An acute angle is an angle that measures less than 90° An obtuse angle is an angle that measures more than 90° but less than180° A straight angle is an angle that measures 180°

13. Tell whether each angle is acute, right, obtuse or straight. Additional Example 2: Classifying Angles Course 2 7-2 Angles A. B. C. right angle obtuse angle acute angle

14. Try This: Example 2 Insert Lesson Title Here Course 2 7-2 Angles Tell whether each angle is acute, right, obtuse, or straight. A. B.C. straight angle acute angle obtuse angle

15. Course 2 7-2 Angles If the sum of the measures of two angles is 90°, then the angles are complementary angles. If the sum of the measures of two angles is 180°, then the angles are supplementary angles.

16. Use the figure to name the following. Additional Example 3A: Identifying Complementary and Supplementary Angles Course 2 7-2 Angles A. one pair of complementary angles Since 30° + 60° = 90°, m OMP = 30° and m OMR = 60° OMP and OMR are complementary. 60° 90° 30° 60° N Q P O R M

17. Use the figure to name the following. Additional Example 3B: Identifying Complementary and Supplementary Angles Course 2 7-2 Angles B. one pair of supplementary angles m RMO = 60° and m QMO = 90° + 30° = 120° Since 60° + 120° = 180°, RMO and QMO are supplementary. 60° 90° 30° 60° N Q P O R M

18. Use the figure to name the following. Try This: Example 3A Course 2 7-2 Angles A. one pair of complementary angles Since 30° + 60° = 90°, m OMP = 30° and m NMQ = 60° OMP and NMQ are complementary. 60° 90° 30° 60° N Q P O R M

19. Use the figure to name the following. Try This: Example 3B Course 2 7-2 Angles B. one pair of supplementary angles m QMP = 90° and m PMR = 30° + 60° = 90° Since 90° + 90° = 180°, QMP and PMR are supplementary. 60° 90° 30° 60° N Q P O R M

20. Lesson Quiz Give the measure of each angle, and tell whether it is acute, obtuse, right, or straight. Insert Lesson Title Here Course 2 7-2 Angles 1. AFB 2. AFC 3.DFC 4. Name a pair of complementary angles. 5. Name a pair of supplementary angles. 90°; right 140°; obtuse DFC and CFB Possible answer: EFA and AFB 40°; acute 50° 40° A B C D E F