angles-.pptx77777777777777777777777777777777777777777

EDUCATION

1. Angles Grade 7 – Mathematics

2. REVIEW

3. An angle is defined as the amount of turn between two rays that share a common end point. Angles are measured in degrees Angles 90°

4. Let’s identify the parts of an angle ! T X

5. Let’s identify the parts of an angle ! V E R T E X

6. Let’s identify the parts of an angle ! R

7. Let’s identify the parts of an angle ! A R M S

8. Let’s identify the parts of an angle ! D G

9. Let’s identify the parts of an angle ! D E G R E E S

10. the common point where the two rays meet vertex the rays that make up the angle arms the measure of the size of an angle degrees

11. Naming Angles 1 One way is to use the  ∠ symbol followed by three letters. The first and third letters indicate points on the two arms .  The letter in the middle is the vertex . ∠ __ __ __ A B C ∠ __ __ __ C B A

12. Naming Angles using the ∠ symbol only with the vertex point.  The angle would be called ∠B. by using the ∠ symbol followed by the letter or number between the angle.  This would be ∠ 1 . 1 ∠ABC ∠CBA ∠CAB ∠ BCA ∠B ∠ 1

13. A B C D 4 5

14. Kinds of Angles acute angle less than 90° obtuse angle more than 90° less than 180° right angle exactly to 90°

15. Kinds of Angles reflex angle more than 180° Full rotation exactly 360° straight angle exactly to 180°

16. acute right obtuse straight

17. Protractor A tool that is used to measure angles. outer scale inner scale center

18. Measuring Angles Place the center of the protractor on the vertex B A B C

19. Measuring Angles Place the center of the protractor on the vertex B A B C Adjust the 0° baseline of the protractor so that it lines up with line BC

20. Measuring Angles Place the center of the protractor on the vertex B A B C Adjust the 0° baseline of the protractor so that it lines up with line BC Since the angle is acute and the 0° line or baseline was used from the right, you will take the reading from the inner scale 30°

21. Measuring Angles

22. Measuring Angles

23. Measuring Angles

24. Measuring Angles

25. Measuring Angles

26. Let’s Review ! These are angles whose measure is exactly 90° acute obtuse right straight

27. Let’s Review ! (90° + 45°) is what kind of angle? acute obtuse right straight

28. Let’s Review ! It is the sum of two right angles. acute obtuse right straight

29. Let’s Review ! These are the rays that make up the angle. degrees arms points vertex

30. Let’s Review ! It is the common point where the two rays meet. degrees arms points vertex

31. Let’s Review ! It is the measure of the size of an angle degrees arms points vertex

32. Let’s Review ! If the points A and B are the arms, what is the name of the angle if point C is the vertex? ∠ ABC ∠ CBA ∠ BAC ∠ ACB

33. Let’s Review ! How many ways can you name the angles on this picture? 9 10 12 13 E F G H I

34. Let’s work together ! It is the only animal that have fingerprints. 5 3 2 1 4 A – 20 ° D – 60 ° E – 35 ° G – 110 ° K – 155 ° L – 120 ° N – 160 ° O – 145 ° P – 25 °

35. Let’s work together ! It is the only animal that have fingerprints. A L A O K 5 3 2 1 4 A – 20 ° D – 60 ° E – 35 ° G – 110 ° K – 155 ° L – 120 ° N – 160 ° O – 145 ° P – 25 °

36. What is the measure of the angle? 20 °

37. 20 ° What is the measure of the angle?

38. 145 ° What is the measure of the angle?

39. What is the measure of the angle? 120 °

40. What is the measure of the angle? 155 °

41. Assignment Search for the following terms and formulas. Write your answers on your notebook. 1. Time 2. A.M. 3. P.M.