1. 2-2 Conditional Statements

2. 2-2 Conditional Statements
Students will both make explicit use of conditional terms, such as “contrapositive,” and find the truth value of different permutations of verbal conditionals.
2-2 Conditional Statements
To recognize conditional statements
To write converses, inverses, and contrapositives of conditional statements

3. Definitions

12. The following questions are designed to help you assess yourself on whether or not you understood today’s lesson.
Be sure to ask me if you miss more than you get right and you do not understand why.
Record the number you get right on your portfolio sheet!
2-2 Quiz

13. 1. Identify the hypothesis and conclusion of this conditional statement: If two lines intersect at right angles, then the two lines are perpendicular.
Hypothesis: The two lines are perpendicular. Conclusion: Two lines intersect at right angles.
Hypothesis: Two lines intersect at right angles Conclusion: The two lines are perpendicular.
Hypothesis: The two lines are not perpendicular Conclusion: Two lines intersect at right angles.
Hypothesis: Two lines intersect at right angles Conclusion: The two lines are not perpendicular.
Non-Response Grid

14. 2. Write this statement as a conditional in if-then form: All triangles have three sides.
If a triangle has three sides, then all triangles have three sides.
If a figure has three sides, then it is not a triangle.
If a figure is a triangle, then all triangles have three sides.
If a figure is a triangle, then it has three sides.
Non-Response Grid

15. 3. Which statement is a counterexample for the following conditional
3. Which statement is a counterexample for the following conditional? If you live in Springfield, then you live in Illinois.
Sara Lucas lives in Springfield.
Jonah Lincoln lives in Springfield, Illinois.
Billy Jones lives in Chicago, Illinois.
Erin Naismith lives in Springfield, Massachusetts.
Non-Response Grid

16. 4. What is the contrapositive of the following conditional
4. What is the contrapositive of the following conditional? If a point is in the first quadrant, then its coordinates are positive.
If a point is in the first quadrant, then its coordinates are positive.
If a point is not in the first quadrant, then the coordinates of the point are not positive.
If the coordinates of a point are positive, then the point is in the first quadrant.
If the coordinates of a point are not positive, then the point is not in the first quadrant.
Non-Response Grid

17. 5. What is the converse and the truth value of the converse of the following conditional? If an angle is a right angle, then its measure is 90.
If an angle is not a right angle, then its measure is 90. False
If an angle is not a right angle, then its measure is not 90. True
If an angle has measure 90, then it is a right angle. False
If an angle has measure 90, then it is a right angle. True
Non-Response Grid

18. 2-2
p.93-94
#6-42 even
Assignment