Trapezoid

In Euclidean geometry, a convex quadrilateral with at least one pair of parallel sides (see definition below) is referred to as a trapezoid in American English and as a trapezium in English outside North America. The parallel sides are called the bases of the trapezoid and the other two sides are called the legs or the lateral sides. A scalene trapezoid is a trapezoid with no equal sides or angles, in contrast to the special cases below. A trapezoid with vertices ABCD is denoted ABCD.