Properties of Parallelograms

G.CO.11 Prove theorems about parallelograms. Theorems include: opposite sides are congruent, opposite angles are congruent, the diagonals of a parallelogram bisect each other...

Goals for this section:

Students should be able to recognize a parallelogram and understand the properties attributed to parallelograms.

What is a parallelogram?

  • Has 4 sides (quadrilateral)
  • Both pairs of opposite sides are parallel

Properties of Parallelograms

Opposite Sides are congruent

  • The top and bottom side have the same length.
  • The left and right side have the same length.

Opposite Angles are congruent

  • The top right angle has the same measure as the bottom left angle.
  • The top left angle has the same measure as the bottom right angle.

Diagonals bisect each other

The diagonals cut each other in half.

External Resources