1. 6.3 Showing Quadrilaterals are Parallelograms Textbook pg 316

2. What are the properties of a parallelogram?

3. Once we know we are dealing with a parallelogram, we can apply all of those properties to the parallelogram. How do we determine if the quadrilateral is a parallelogram in the first place if no one tells us?

4. Definition of a Parallelogram: a quadrilateral with both pairs of opposite sides parallel Parallelogram

5. If both pairs of opposite sides of a quadrilateral are congruent, then it is a parallelogram Parallelogram

6. If both pairs of opposite angles of a quadrilateral are congruent, then it is a parallelogram Parallelogram

7. If all pairs of consecutive angles of a quadrilateral are supplementary, then it is a parallelogram Parallelogram xoxo yoyo yoyo xoxo x o + y o = 180 o

8. If the diagonals of a quadrilateral bisect EACH OTHER, it is a parallelogram Parallelogram

9. Practice Problems on pg 317 & 319 1) Yes, opposite sides are congruent 2) No, opposite angles are not congruent OR ALL consecutive angles are not necessarily supplementary 3) No, opposite sides are not congruent 4) No, opposite angles are not congruent 5) Yes, opposite angles are congruent AND consecutive angles are supplementary 6) Yes, diagonals bisect each other 7) No, diagonals do not bisect each other

10. Homework Assignment # 12 Pg 320 problems 1-21 all, 28-44 all