1. Splash Screen

2. Lesson Menu Five-Minute Check (over Lesson 9–2) Main Idea and Vocabulary Example 1:Find a Missing Angle Measure Key Concept: Pairs of Angles Example 2:Classify Pairs of Angles Example 3:Classify Pairs of Angles Example 4:Find Missing Angle Measures Example 5:Find Missing Angle Measures

3. Main Idea/Vocabulary vertical angles congruent angles supplementary angles complementary angles Classify and apply angle relationships.

4. Example 1 Find a Missing Angle Measure What is the value of x in the figure below? The angle labeled x  and the angle labeled 110  are vertical angles. Therefore, they are congruent. Answer: So, the value of x is 110.

5. 1.A 2.B 3.C 4.D Example 1 A.45 B.85 C.90 D.225 What is the value of x in the figure?

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7. Example 2 Classify Pairs of Angles Classify the pair of angles as complementary, supplementary, or neither. 60° + 30° = 90° Answer: Since the sum of their measures is 90°, the angles are complementary.

8. 1.A 2.B 3.C Example 2 A.complementary B.supplementary C.neither Classify the pair of angles as complementary, supplementary, or neither.

9. Example 3 Classify Pairs of Angles Classify the pair of angles as complementary, supplementary, or neither. 110° + 40° = 150° Answer: Since the sum of their measures is not 90° or 180°, the angles are neither complementary nor supplementary.

10. 1.A 2.B 3.C Example 3 A.complementary B.supplementary C.neither Classify the pair of angles as complementary, supplementary, or neither.

11. Example 4 Find Missing Angle Measures Find the value of x in the figure. Since the angles form a straight line, they are supplementary. Answer: So, the value of x is 95. 85° + x° = 180°Definition of supplementary angles 85° + 95° = 180°THINK What measure added to 85° equals 180°?

12. 1.A 2.B 3.C 4.D Example 4 A.70 B.90 C.110 D.180 Find the value of x in the figure.

13. Example 5 Find Missing Angle Measures Find the value of x in the figure. Answer: So, the value of x is 20. Since the angles form a right angle, they are complementary. 70° + x° = 90°Definition of complementary angles 70° + 20° = 90°THINK What measure added to 70° equals 90°?

14. 1.A 2.B 3.C 4.D Example 5 A.25 B.45 C.110 D.180 Find the value of x in the figure.

15. End of the Lesson

16. Resources Five-Minute Check (over Lesson 9–2) Image Bank Math Tools Estimating Angles Angles in Triangles

17. 1.A 2.B 3.C 4.D Five Minute Check 1 A.about 40° B.about 110° C.about 140° D.about 170° Refer to the figure. Estimate the measure of the angle. (over Lesson 9-2)

18. 1.A 2.B 3.C 4.D Five Minute Check 2 A.about 50° B.about 30° C.about 10° D.about 5° Refer to the figure. Estimate the measure of the angle. (over Lesson 9-2)

19. 1.A 2.B 3.C 4.D Five Minute Check 3 Which choice shows a 45° angle? (over Lesson 9-2) A.B. C.D.

20. 1.A 2.B 3.C 4.D Five Minute Check 4 Which choice shows a 125° angle? (over Lesson 9-2) A.B. C.D.

21. 1.A 2.B 3.C 4.D Five Minute Check 5 Which choice shows an 87° angle? (over Lesson 9-2) A.B. C.D.

22. 1.A 2.B 3.C 4.D Five Minute Check 6 A.about 12° B.about 15° C.about 17° D.about 18° Estimate the measure of the angle formed by the hands of a clock at 6:25 A.M. (over Lesson 9-2)

23. End of Custom Shows