 Parallelograms are quadrilaterals, this means they have 4 sides

 Opposite sides are congruent  Opposite angles are congruent  Consecutive angles are supplementary  Diagonals bisect each other

 Notice the height forms a right angle with the sides.  There is a potential for using the Pythagorean theorem of sin, cos, or tan to solve

 Rectangle  Rhombus  Square  All are special types of parallelograms and will have all the properties listed for a parallelogram as well as additional properties specific to that figure