2. Angle Measurement Lesson 2b next

3. Definitions: A.A ray is the part of a line consisting of one endpoint and all the points of the line on one side of the endpoint. B.A ray goes on forever in one direction without ending. C.A ray is named by first stating the endpoint and then one other point in the direction of the ray. D.For example, the ray above could be named-- A B Ray AB or AB I.Ray next

4. Definitions Cont. B C A A.An angle is formed by two rays with the same endpoint. B.The two rays are called the sides of the angle. C.The common endpoint is called the vertex. II.Angle next

5. Definitions Cont. B C A When naming an angle: 1)The middle letter is always the vertex. 2)The first letter is one point on one of the rays. 3)The last letter is one point on the other ray. II.Angle cont... D.An angle is named a few different ways: For our purposes we will most often use three points to name an angle. E.For example, the angle above could be named:  BAC. next

6. Definitions Cont. B C A A.Figures that have the same size & same shape are congruent (  ). B.Segments are congruent if they are the same length. C.Angles are congruent if they are the same degree measure. III.Congruence next D.  ROC is congruent to  XYZ. This can be written,  ROC   XYZ. R O C X Y Z 48º

7. Angle Measurement: A.The symbol for degree is a small raised zero (°). B.We use a protractor to measure angles. Protractor 40° I. Angles are measured using units called degrees. next

8. Angle Measurement cont… II.Angles can be classified according to their measure. next

9. Angles less than 90° are called Acute Angles. Angles equal to 180° are called Straight Angles. Angle Measurement cont… Acute Angle: Obtuse Angle: Right Angle:Straight Angle: Types of Angles: Angles greater than 90° are called Obtuse Angles. Symbol for right angle 180° Angles equal to 90° are called Right Angles. next

10. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Next

11. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Choose the correct measure. 160°20° or Next

12. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! 20° Next 20°

13. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. How would you classify this angle? Next Click here to review Angle Types ObtuseAcuteRightStraight Choose one! 20°

14. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! Acute Click here to review Angle Types Next Angle 20° Angles less than 90° are called Acute Angles.

15. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Next

16. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Choose the correct measure. 130°50° or Next

17. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! 130° Next 130°

18. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Click here to review Angle Types How would you classify this angle? Next ObtuseAcuteRightStraight Choose one! 130°

19. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! Obtuse Click here to review Angle Types Next Angle 130° Angles greater than 90° are called Obtuse Angles.

20. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Next

21. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Choose the correct measure. 118°60° Next 62°78°

22. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! 62° Next 62°

23. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. How would you classify this angle? Next Angle Click here to review Angle Types ObtuseAcuteRightStraight Choose one! 62°

24. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! Acute Click here to review Angle Types Next Angle 62° Angles less than 90° are called Acute Angles.

25. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Next

26. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Choose the correct measure. 180°90° Next 0°0°110°

27. 90° Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! 90° Next 90°

28. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. How would you classify this angle? Next Click here to review Angle Types ObtuseAcuteRightStraight Choose one!

29. 90° Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. That’s Correct! Right Click here to review Angle Types Next Angles equal to 90° are called Right Angles.

31. Angles less than 90° are called Acute Angles. Angles equal to 180° are called Straight Angles. Angles equal to 90° are called Right Angles. Angle Measurement cont… Acute Angle: Obtuse Angle: Right Angle:Straight Angle: Types of Angles: Angles greater than 90° are called Obtuse Angles. Symbol for right angle 180° Back

32. Angle Measurement cont… Click on the protractor to measure each angle, then classify the angle as acute, right, obtuse, or straight. Sorry Try Again! Back