parallélogramme

A parallelogram is a quadrilateral with two pairs of parallel sides. This means that opposite sides are equal in length and opposite angles are equal in measure. The diagonals of a parallelogram bisect each other, meaning they intersect at their midpoints.

There are several special types of parallelograms. A rectangle is a parallelogram with four right angles. A rhombus is a parallelogram with four equal sides. A square is both a rectangle and a rhombus, possessing four right angles and four equal sides.

The area of a parallelogram can be calculated by multiplying its base by its height. The perimeter of a parallelogram is twice the sum of the lengths of two adjacent sides.

In Euclidean geometry, parallelograms are fundamental shapes. Their properties are used in various geometric proofs and constructions. The concept extends to higher dimensions and abstract algebra, where generalized parallelograms can be defined. The term "parallelogram" originates from the Greek words "parallēlos" (parallel) and "grammē" (line).