A quadrilateral with two sets of parallel sides is known as a parallelogram.
In geometry, a parallelogram is a four-sided figure where opposite sides are both equal in length and parallel. This property of parallelism leads to some interesting characteristics: the opposite angles are equal, the adjacent angles are supplementary (adding up to 180 degrees), and the diagonals bisect each other. Common examples of parallelograms include rectangles, rhombuses, and squares, each of which possesses unique properties while still maintaining the fundamental characteristics of a parallelogram.