2. Lesson Menu Main Idea and New Vocabulary NGSSS Key Concept:Types of Angles Example 1:Name Angles Key Concept:Pairs of Angles Example 2:Real-World Example Example 3:Find a Missing Angle Measure Five-Minute Check

3. Main Idea/Vocabulary Classify angles and identify vertical and adjacent angles. congruent vertex acute angle right angle obtuse angle straight angle vertical angles adjacent angles

4. NGSSS MA.8.G.2.2 Classify and determine the measure of angles, including angles created when parallel lines are cut by transversals.

5. Key Concept

6. Example 1 Name Angles Name the angle below in four ways. Then classify it as acute, right, obtuse, or straight. Use the vertex as the middle letter and a point from each side,  FGH or  HGF. Use the vertex only,  G. Use a number,  2. Since the angle is less than 90°, it is an acute angle.

7. Example 1 Name Angles Answer:  FGH,  HGF,  G,  2; acute

8. Example 1 CYP A.  JKL,  K; acute B.  LKJ,  K; right C.  JKL,  K; obtuse D.  LKJ,  J; obtuse Name the angle below in two ways. Then classify it as acute, right, obtuse, or straight.

9. Key Concept 2

10. Example 2 SEWING Identify a pair of vertical angles and adjacent angles in the diagram. Justify your response. Answer:  3 and  5 are vertical angles because they are opposite angles formed by intersecting lines.  4 and  5 are adjacent angles because they share a common side.

11. Example 2 CYP A.vertical:  5 and  7 adjacent:  5 and  8 B.vertical:  5 and  8 adjacent:  6 and  7 C.vertical:  6 and  7 adjacent:  5 and  8 D.vertical:  6 and  7 adjacent:  7 and  8 HIKING Identify a pair of vertical angles and adjacent angles in the diagram of the hiking trails.

12. Example 3 Find a Missing Angle Measure What is the value of y in the figure below? The angle labeled y and the angle labeled 60  are vertical angles. Since vertical angles are congruent, the value of y is 60 . Answer: 60°

13. Example 3 CYP A.14° B.76° C.104° D.180° What is the value of x in the figure below?

14. A.acute B.right C.obtuse D.straight Classify the angle as acute, right, obtuse, or straight. Five Minute Check 1

15. A.acute B.right C.obtuse D.straight Classify the angle as acute, right, obtuse, or straight. Five Minute Check 2

16. A.acute B.right C.obtuse D.straight Classify the angle as acute, right, obtuse, or straight. Five Minute Check 3

17. A.  1 and  2 B.  1 and  3 C.  2 and  3 D.  1 and  4 Identify a pair of vertical angles. Five Minute Check 4

18. A.true B.false Tell whether the following statement is true or false. A straight angle has a measure of 180°. Five Minute Check 5

19. A.  1 and  3 B.  2 and  3 C.  2 and  4 D.none of the above Which of the angles shown in the diagram are adjacent? Five Minute Check 6