1. Chapter 5 Parallel Lines and Related Figures
5.1 Indirect Proof
Learner Objective: Students will prove statements using "Indirect Proof".

2. Warm-Up Prove: Given: M is the midpoint of
Learner Objective: Students will prove statements using "Indirect Proof".
Warm-Up
Given:
M is the midpoint of
Prove: D A C B M

3. Either ________ or _________.
Learner Objective: Students will prove statements using "Indirect Proof".
Given:
Either ________ or _________.
Assume _________.
From the given information,
Prove: A B C
Thus,
But this contradicts D E F
Therefore, my assumption was false and 
_________, because this is the only 
other possibility.

4. Indirect Proof Template
Learner Objective: Students will prove statements using "Indirect Proof".
Indirect Proof Template
Either or
What you want to prove
Opposite of what you want to prove.
Assume
Opposite of what you want to prove.
We know from the given information that
We know that
Thus
Then
A chain of conclusions and reasons until you 
reach an impossibility. This will be a contradiction 
of either
(a) given information or
(b) a theorem, definition, or other known fact.
But this contradicts
The know fact that has been contradicted.
Therefore my assumption was false and
because this is the only other possibility.
the statement you have proved

5. Indirect Proof Procedure:
Learner Objective: Students will prove statements using "Indirect Proof".
Indirect Proof Procedure:
1. List the possibilities for the conclusion.
2. Assume that the negation of the desired conclusion is correct.
3. Write a chain of reasons until you reach a contradiction of
  a. Given information or
  b. A theorem, definition, or other known fact.
4. State the remaining possibility as the desired conclusion.

6. We know from the given information that Then But this contradicts
Learner Objective: Students will prove statements using "Indirect Proof".
Either or
Assume
 We know from the given information that
 Then  
 But this contradicts
 Therefore, my assumption was false and
 since that is the only other possibility.

7. Learner Objective: Students will prove statements using "Indirect Proof".

8. Learner Objective: Students will prove statements using "Indirect Proof".
Assignment
 5.1: 1, 2, 5-12, 15

9. Learner Objective: Students will prove statements using "Indirect Proof".

10. Learner Objective: Students will prove statements using "Indirect Proof".

11. Learner Objective: Students will prove statements using "Indirect Proof".

12. Learner Objective: Students will prove statements using "Indirect Proof".

13. Learner Objective: Students will prove statements using "Indirect Proof".

14. Learner Objective: Students will prove statements using "Indirect Proof".

15. Learner Objective: Students will prove statements using "Indirect Proof".

16. Learner Objective: Students will prove statements using "Indirect Proof".

17. Learner Objective: Students will prove statements using "Indirect Proof".

18. Learner Objective: Students will prove statements using "Indirect Proof".

19. Learner Objective: Students will prove statements using "Indirect Proof".

20. Learner Objective: Students will prove statements using "Indirect Proof".

21. Learner Objective: Students will prove statements using "Indirect Proof".

22. Learner Objective: Students will prove statements using "Indirect Proof".

23. Learner Objective: Students will prove statements using "Indirect Proof".

24. Learner Objective: Students will prove statements using "Indirect Proof".

25. Learner Objective: Students will prove statements using "Indirect Proof".

26. Learner Objective: Students will prove statements using "Indirect Proof".

27. Learner Objective: Students will prove statements using "Indirect Proof".

28. Learner Objective: Students will prove statements using "Indirect Proof".

29. Learner Objective: Students will prove statements using "Indirect Proof".

30. Learner Objective: Students will prove statements using "Indirect Proof".

31. Learner Objective: Students will prove statements using "Indirect Proof".

32. Learner Objective: Students will prove statements using "Indirect Proof".

33. Learner Objective: Students will prove statements using "Indirect Proof".

34. Learner Objective: Students will prove statements using "Indirect Proof".