Parallelogram

(Jump to Area of a Parallelogram or Perimeter of a Parallelogram)

A Parallelogram is a flat shape with opposite sides parallel and equal in length.

Parallelogram

right arrow Opposite sides are parallel
right arrow

Opposite sides are equal in length

right arrow Opposite angles are equal (angles A are the same, and angles B are the same)
right arrow Angle A and angle B add up to 180°, so they are supplementary angles.

Play with a Parallelogram:

images/geom-quad.js?mode=parallelogram

NOTE: Squares, Rectangles and Rhombuses are all Parallelograms!

Rectangle

Example:

A parallelogram where all angles are right angles is a rectangle!

Area of a Parallelogram

parallelogram base and height  

The Area is the base times the height:

Area = b × h

(h is at right angles to b)

Example: A parallelogram has a base of 6 m and is 3 m high, what is its Area?

Area = 6 m × 3 m = 18 m2

Perimeter of a Parallelogram

The Perimeter is the distance around the edges.

parallelogram perimeter  

The Perimeter is 2 times the (base + side length):

Perimeter = 2(b+s)

Example: A parallelogram has a base of 12 cm and a side length of 6 cm, what is its Perimeter?

Perimeter = 2 × (12 cm + 6 cm) = 2 × 18 cm = 36 cm

Diagonals of a Parallelogram

parallelogram diameter bisect

The diagonals of a parallelogram bisect each other.

In other words the diagonals intersect each other at the half-way point.

Pantograph

Based on a parallelogram, a pantograph can be used to duplicate and resize an image by tracing.

pantograph

Inside Any Quadrilateral

And there is a parallelogram in any quadrilateral.

 

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