What are the four properties of parallelograms?

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