1. 6.2 Properties of parallelograms

2. Parallelogram
A quadrilateral with both pairs of opposite sides parallel. We will use this symbol to shorten things up…
The following are several theorems that are true for all parallelograms, they can be proven (which we will do) by using what we have learned about parallel lines and congruent triangles.

3. Theorem
Opposite sides of a parallelogram are congruent.

4. proof
Given: EFGH
Prove:

5. Theorem
Opposite angles of a parallelogram are congruent

6. Theorem
Diagonals of a parallelogram bisect each other

7. Proof Given: QRST with diagonals QS and TR1 3
Given: QRST with diagonals QS and TR
Prove: QS and TR bisect each other 4 2

8. Theorem Consecutive angles in a parallelogram are supplementary.
-Think about why?