3. Ray An object that has one endpoint and continues infinitely in ONE direction.

4. Angle An object that has two rays (called sides) with a common endpoint (called the vertex).

5. Example 1 Name each of the following: Sides:_____________________ Vertex:_________ Name:_____________________ A B C

6. Interior of an Angle the space between the rays that create an angle.

7. Exterior of an Angle the space that is outside of the rays

8. Example 2 How does the diagram in EXAMPLE 1 differ from the diagram in this example? Q P R S

9. Example 3 A) Name a point in the interior of  QPS in EXAMPLE 2. B) Name a point in the exterior of  QPR in EXAMPLE 2. Q P R S

10. Adjacent To be next to. SHARING a side.

11. Angle Addition Postulate The sum of two adjacent angles is equal to the largest angle.

12. ANGLE ADDITION POSTULATE: Q P R S If R is in the interior of  QPS, then m  QPR + m  RPS = m  QPS. If m  QPR + m  RPS = m  QPS, then R is in the interior of  QPS.

13. ANGLE ADDITION POSTULATE: Q P R S If R is in the interior of  QPS, then m  QPR + m  RPS = m  QPS. If m  QPR + m  RPS = m  QPS, then R is in the interior of  QPS.

14. Example 4 If m  PQS = 77  and m  PQR = 32 , then find m  RQS. P Q R S

15. Example 5 If m  AOC = 70 , m  AOB =(x + 10) , and m  BOC =x , find: x = __________ m  BOC = _______________ m  AOB = _______________ O A B C

16. Angles can be classified by their measure in degrees. If an angle has a degree measure less than 90° it is classified as an _acute angle__. If an angle has a degree measure equal to 90° it is classified as a __ right angle ____.

17. Acute Angle An angle measuring less than 90°

18. Right Angle An angle whose measure is exactly 90°

19. Obtuse Angle An angle measuring greater than 90° but less than 180°

20. Straight Angle An angle measuring exactly 180°

21. For each of the following angles A) Name it. B) Tell whether its measure is 90 , =90 , or = 180 . C) Classify it. NAME:_________ OR ______ MEASURE:________ CLASSIFICATION___________ F Y I NAME:_________ OR ______ MEASURE:________ CLASSIFICATION___________ T L C NAME:_________ OR ______ MEASURE:________ CLASSIFICATION___________ T R S NAME:_________ OR ______ MEASURE:________ CLASSIFICATION___________ N X S 35  125 

22. Congruent to be the same shape and same size.

23. Angle Bisector a line, ray, or segment that divides an angle into two congruent angles.

24. Example 7 If XZ is an angle bisector of  WXY, name the two congruent angles that it forms. W X Z Y

25. Example 8 FG bisects  EFH. Find the value of x. m  EFG = (5x – 10)  ; m  GFH = (3x + 25)  I FH E G

26. Example 9 FG bisects  EFH. Find the value of x. m  GFH = (3x + 20)  ; m  EFH = (4x + 80)  I FH E G