The parallelogram symbol is a geometric shape which has four sides and four angles. Every two opposite sides are parallel to each other and are equal in length; every two opposite angles are equal in measurement too. Adjacent angles supplement each other.

Diagonals which are drawn inside the parallelogram divide each other into two halves. Diagonal divides the parallelogram into two identical triangles.

The summation of the sides squared is equal to the summation of the diagonal squared. These properties are applied to all parallelogram shapes. If one of the previous terms is true, then the given shape is a parallelogram.