1. Proving That a Quadrilateral Is a Parallelogram

2. Proving That a Quadrilateral Is a Parallelogram

3. Proving That a Quadrilateral Is a Parallelogram

4. Proving That a Quadrilateral Is a Parallelogram

5. Proving That a Quadrilateral Is a Parallelogram

6. Proving That a Quadrilateral Is a Parallelogram

7. Proving That a Quadrilateral Is a Parallelogram
Problem 1:
For what value of y must PQRS be a parallelogram?

8. Proving That a Quadrilateral Is a Parallelogram
Problem 1b:
For what value of x and y must ABCD be a parallelogram?

9. Proving That a Quadrilateral Is a Parallelogram
Problem 1c:
For what value of x and y must ABCD be a parallelogram?

10. Proving That a Quadrilateral Is a Parallelogram
Problem 1d:
For what value of x and y must ABCD be a parallelogram?

11. Proving That a Quadrilateral Is a Parallelogram
Problem 1e:
For what value of x and y must ABCD be a parallelogram?

12. Proving That a Quadrilateral Is a Parallelogram
Problem 2:
Can you prove that the quadrilateral is a parallelogram based on the given information? Explain!

13. Proving That a Quadrilateral Is a Parallelogram
Problem 2:
Can you prove that the quadrilateral is a parallelogram based on the given information? Explain!

14. Proving That a Quadrilateral Is a Parallelogram
Problem 3:
A truck sits on the platform of a vehicle lift. Two moving arms raise the platform until a mechanic can fit underneath. Why will the truck always remain parallel to the ground as it is lifted? Explain!

15. Proving That a Quadrilateral Is a Parallelogram

16. Proving That a Quadrilateral Is a Parallelogram