1. Module 2 part 2 Properties of Angles

2. M2L12: Angles Associated with Parallel Lines

8. Do Problem Set # 1-10 ●Answer each problem thoroughly and in complete sentences

11. M2L13: Angle Sum of a Triangle

12. Objectives: ●Students know the angle sum theorem for triangles; the sum of the interior angles of a triangle is always 180 degrees. ●Students present informal arguments to draw conclusions about the angle sum of a triangle.

13. ●In pairs, answer questions a through e

14. Challenge answers

15. Challenge answers:

16. Exploratory Challenge 2 ●Answer questions a through c

17. Challenge Answers

18. Lesson Summary ●All triangles have a sum of interior angles equal to 180 degrees ●We can prove that a triangle has a sum of interior angles equal to that of a straight angle using what we know about alternate interior angles and corresponding angles of parallel lines.

19. M2L13 Problem Set ●Complete problems 1-9 ●Answer thoroughly and in complete sentences.

20. Problem Set Answers

22. 3.

26. M2L14: More on the Angles of a Triangle Warm-Up: What properties do rectangles have? What shapes do we get when we draw a diagonal?

27. Discussion

28. Exercise Answers

29. Exercise Answers:

30. ●What do we need to do the solve for angle x?

31. ●Find angle x ●show work on whiteboard

32. ●What do we need to solve for x? o (it’s different than before)

33. ●Find measure of angle x o it’s different than the last three examples

34. Mind time: Exercises 5-10

38. Lesson Summary: ●We learned another proof as to why the interior angles of a triangle are equal to 180º with respect to a triangle being exactly half of a rectangle. ●We learned the definitions of exterior angles and remote interior angles. ●The sum of the remote interior angles of a triangle is equal to the measure of the related exterior angle.

39. M2L14 Problem Set #1-10

40. Problem Set Answers: 1.