ETYM Greek; parallel + grafein to write: cf. French parallélogramme. Related to Parallel, and -gram.
A quadrilateral whose opposite sides are both parallel and equal in length.
In mathematics, a quadrilateral (four-sided plane figure) with opposite pairs of sides equal in length and parallel, and opposite angles equal. The diagonals of a parallelogram bisect each other. Its area is the product of the length of one side and the perpendicular distance between this and the opposite side. In the special case when all four sides are equal in length, the parallelogram is known as a rhombus, and when the internal angles are right angles, it is a rectangle or square. + prikaži više