3. Objective: Know the sum of angles at a point, on a straight line and in a triangle. Vocabulary:

5. 90 0

7. 40 0 ?0?0 50 0

8. 30 0 55 0 72 0 63 0 53 0

9. 30 0 55 0 72 0 63 0 51 0 60 0 35 0 18 0 27 0 39 0

10. 180 0

12. 50 0 ?0?0 130 0

13. 55 0 60 0 115 0 35 0 112 0

14. 55 0 60 0 115 0 35 0 112 0 125 0 120 0 65 0 68 0 145 0

15. 360 0

16. 55 0 305 0

17. 55 0 215 0 90 0 + 55 0 = 145 0 360 0 – 145 0 = 215 0

18. 85 0 275 0 115 0 245 0 85 0 50 0 75 0 190 0 145 0

19. ruler

20. The sum of the angles in a triangle is 180 0

22. 85 0 50 0 ? 85 0 + 50 0 = 135 0 180 0 – 135 0 = 45 0 ? = 45 0

23. The sum of the angles in a triangle is 180 0 110 0 30 0 ? 30 0 + 110 0 = 140 0 180 0 – 140 0 = 40 0 ? = 40 0

24. The sum of the angles in a triangle is 180 0 52 0 55 0 ? 55 0 + 52 0 = 107 0 180 0 – 107 0 = 73 0 ? = 73 0

25. The sum of the angles in a triangle is 180 0 60 0 75 0 ? 75 0 + 60 0 = 135 0 180 0 – 135 0 = 45 0 ? = 45 0

26. Thank you for your attention