Notes

 

In Summary

There are 5 ways to proves quadrilaterals are parallelograms. You must demonstrate that the quadrilateral has one the the following properties.

\(\bullet\) Both pairs of opposite sides are congruent.
\(\bullet\) Both pairs of opposite sides are parallel.
\(\bullet\) Both pairs of opposite angles are congruent.
\(\bullet\) One pair of opposite sides are both congruent and parallel.
\(\bullet\) The diagonals bisect eachother.