Properties of parallelogram

Objective : 

To explore similarities and differences in the properties with respect to diagonals of the following quadrilaterals- a parallelogram, a square, a rectangle and a rhombus.

Definition:

It is a quadrilateral where both pairs of opposite sides are parallel. Quadrilateral ABCD is a parallelogram.

Properties :

  • A diagonal of a parallelogram divides it into two congruent triangles (▲ ADC is congruent to ▲ ABC).
  • Diagonals of a parallelogram bisect each other.
  • Opposite sides are congruent (AB = DC).
  • Opposite angles are congruent (∠ADC= ∠ABC).
  • Consecutive angles are supplementary (∠DAB + ∠ADC = 180°).
  • If one angle is right angle, then all angles are right.