1. Warm-Up ABCD is a parallelogram. AB = 12 and BC = 25
What is the perimeter of the figure? 25 12

2. Conditions for Parallelograms
Geometry 6-3
Conditions for Parallelograms

3. Conditions for Parallelograms
A quadrilateral is a parallelogram if…
One pair of opposite sides is
parallel and congruent
Both pairs of opposite sides
are congruent
Both pairs of opposite angles

4. …continued An angle is supplementary to both of its consecutive angles
The diagonals bisect
each other

5. Example
Show that JKLM is a parallelogram for a = 3 and b = 9.

6. Example
Show that PQRS is a parallelogram for x = 10 and y = 6.5.

7. Example
What other pieces of information must you know to prove that quadrilateral KLMN is a parallelogram?