# 2D shapes – parallelogram

A parallelogram is a quadrilateral (a four-sided polygon) with two pairs of parallel sides. This means that the opposite sides of a parallelogram are equal in length and parallel to each other. The opposite angles of a parallelogram are also equal in measure.

Some common properties of parallelograms include:

• The opposite sides of a parallelogram are congruent (equal in length)
• The opposite angles of a parallelogram are congruent (equal in measure)
• The consecutive angles of a parallelogram are supplementary (add up to 180 degrees)
• The diagonals of a parallelogram bisect each other (divide each other into two equal parts)
• The area of a parallelogram can be calculated as base x height, where the base is the length of one of the sides and the height is the perpendicular distance between that side and its opposite side.

Parallelograms are commonly used in geometry, trigonometry, and other branches of mathematics. They can also be found in many real-world objects, such as windows, doors, and boxes.