There are six important properties of parallelograms to know:
Opposite sides are congruent (AB = DC).Opposite angels are congruent (D = B).Consecutive angles are supplementary (A + D = 180°).If one angle is right, then all angles are right.The diagonals of a parallelogram bisect each other.Each diagonal of a parallelogram separates it into two congruent triangles.
Opposite sides are parallel by definition Opposite sides are congruent opposite angles are congruent consecutive angles are supplementary The diagonals bisect each other
