1. Warm up 1.Re-write the following statements as an if-then statement. 2.State the converse of the statement. a.The midpoint of a segment is a point that divides the segment into two congruent segments b.Two angles are complementary if the sum of their measures is 90 degrees c.In an equilateral polygon, all sides are congruent Homework: pg 83; 16-21 and 25-29

2. Converse- inverse- contrapositive Converse- exchange the hypothesis and the conclusion Ex- if the water temperature is below 0 ⁰C, then it is frozen Inverse- negate both the hypothesis and the conclusion Ex: If water is not frozen, then its temperature is not below 0 ⁰C Contrapositive- negate the hypothesis and conclusion of the converse Ex: if the water temperature is not below 0 ⁰C, then it is not frozen Ex: if water is frozen, then its temperature is below 0⁰C.

3. Hmwk-pg 83; 7-10 7) Complementary angles add to 90 degrees If-then _____________________________________________________ Converse ___________________________________________________ Inverse _____________________________________________________ Contrapositive _______________________________________________ 9) 3x + 10 = 16, because x = 2 If-then _____________________________________________________ Converse ___________________________________________________ Inverse _____________________________________________________ Contrapositive _______________________________________________

4. Guitar players are musicians… If-then Converse Inverse Contrapositive True/false?

5. With a partner… If a polygon is equilateral, then it is regular. Converse- Inverse- Contrapositive- Equivalent statements- both are true or both are false

6. Biconditional statements When a conditional statement and the converse are both true Use the phrase “if and only if” Ex: If two lines intersect to form a right angle, then they are perpendicular lines Converse- Biconditional- two lines are perpendicular _____________ they intersect to form a right angle

7. Biconditionals Definition of right angle The midpoint of a segment is a point that divides the segment into two congruent segments Two angles are complementary if the sum of their measures is 90 degrees In an equilateral polygon, all sides are congruent