Explain the properties of parallelograms.

If a quadrilateral has a pair of parallel opposite sides, then it is called Parallelogram.

• The opposite sides are congruent.
• The opposite angles are congruent.
• The consecutive angles are supplementary.
• If anyone of the angles is a right angle, then all the other angles will also be right angles.
• The two diagonals bisect each other.
  
• Each diagonal bisects the parallelogram into two congruent triangles.  

AB=CD and AD=BC

Angle A=Angle C and Angle B=Angle D

Angle A+Angle B=180°, Angle A+Angle D=180°, Angle B+Angle C=180° and Angle C+Angle D=180°.