2. LINES AND ANGLES

3. CAN YOU DRAW A LINE SEGMENT

4. I EXTENDED INDEFINETLY ON BOTH SIDES
DIFFERENTIATE BETWEEN A LINE AND LINE SEGMENT
I AM MADE UP OF POINTS.
I HAVE TWO END POINTS.
I HAVE DEFINETE LENGTH
I AM MADE UP POINTS .
I HAVE NO END POINTS,
I EXTENDED INDEFINETLY ON BOTH SIDES
LINE
LINE SEGMENT

5. ANGLES TWO RAYS WITH A COMMON END POINTS FORM AN ANGLIE
TWO RAYS ARE THE ARMS OF THE ANGLE.
COMMON ENDPOINT IS THE VERTEX OF THE ANGLE

6. There are four main types of angles.
Right angle
Acute angle
Obtuse angle A B C A B C A B C
Straight angle B A C

7. Acute angle: An angle whose measure is less than 90 degrees.

8. Examples Of Acute Angle

9. Right angle: An angle whose measure is 90 degrees.

10. Examples Of Right Angle

11. Obtuse angle: An angle whose measure is greater than 90 degrees.

12. Examples Of Obtuse Angle

13. Straight angle: An angle whose measure is 180 degrees.

14. Examples Of Straight Angle

15. Vertically opposite angles Complimentary angles
Pairs Of Angles : Types
Adjacent angles
Vertically opposite angles
Complimentary angles
Supplementary angles
Linear pairs of angles

16. Adjacent Angles ABC and DEF are not adjacent angles
Two angles that have a common vertex and a common ray are called adjacent angles. C D B A
Common ray
Common vertex D E F A B C
Adjacent Angles ABD and DBC
ABC and DEF are not adjacent angles
Adjacent angles do not overlap each other.

17. Adjacent angles are “side by side” and share a common ray.
15º
45º

18. These are examples of adjacent angles.
45º
80º
35º
55º
130º
50º
85º
20º

19. These angles are NOT adjacent.
100º
50º
35º
35º
55º
45º

20. ÐABC and ÐDEF are complimentary because
Complimentary Angles
If the sum of two angles is 900, then they are called complimentary angles.
600 A B C
300 D E F
ÐABC and ÐDEF are complimentary because
ÐABC + ÐDEF
= 900

21. ÐDEF and ÐPQR are not complimentary because
Contd….
If the sum of two angles is more than 900 or less than 900, then they not complimentary angles.
700 D E F
300 p Q R
ÐDEF and ÐPQR are not complimentary because
ÐDEF + ÐPQR
= 1000

22. ÐPQR and ÐABC are supplementary, because
Supplementary Angles
If the sum of two angles is 1800 then they are called supplementary angles. R Q P A B C
1000
800
ÐPQR and ÐABC are supplementary, because
ÐPQR + ÐABC
= 1800

23. ÐDEF and ÐPQR are not supplementary because
Contd….
If the sum of two angles is more than or less than 1800, then they are not supplementary angles. C B A
1100 D E F
800
ÐDEF and ÐPQR are not supplementary because
ÐABC + ÐDEF
= 1900

24. Two adjacent supplementary angles are called linear pair of angles.
1200
600 C D P
ÐAPC + ÐAPD
= 1800

25. VERTICALLY OPPOSITE ANGLES ARE EQUAL
WHEN TWO LINES INTERSECT THEY MAKE TWO PAIRS OF VERTICALLY OPPOSITE ANGLES
75º
105º
VERTICALLY OPPOSITE ANGLES ARE OPPOSITE TO ONE ANOTHER
VERTICALLY OPPOSITE ANGLES ARE EQUAL

26. Adjacent angles: ÐAPC and ÐCPD
Name the vertically opposite angles and adjacent angles in the given figure: A D B C P
Vertically opposite angles: ÐAPC and ÐBPD
Adjacent angles: ÐAPC and ÐCPD
ÐAPB and ÐCPD
ÐAPB and ÐBPD

27. Directions: Identify each pair of angles as vertical, supplementary, complementary, or none of the above.

28. #1
120º
60º

29. #1
120º
60º
Supplementary Angles

30. #2
60º
30º

31. #2
60º
30º
Complementary Angles

32. #3
75º
75º

33. #3
Vertical Angles
75º
75º

34. #4
60º
40º

35. #4
60º
40º
None of the above

36. #5
60º
60º

37. #5
60º
60º
Vertical Angles

38. #6
135º
45º

39. #6
135º
45º
Supplementary Angles

40. #7
25º
65º

41. #7
25º
65º
Complementary Angles

42. #8
90º
50º

43. #8
90º
50º
None of the above

44. Directions: Determine the missing angle.

45. #1 ?º
45º

46. #1
135º
45º

47. #2 ?º
65º

48. #2
25º
65º

49. #3 ?º
35º

50. #3
35º
35º

51. #4 ?º
50º

52. #4
130º
50º

53. #5 ?º
140º

54. #5
140º
140º

55. #6 ?º
40º

56. #6
50º
40º