trapezoidale

Trapezoidale is an adjective used to describe a shape resembling a trapezoid, a quadrilateral that has a pair of parallel sides. The two parallel sides are called the bases, and the other two sides are the legs. The distance between the bases, the height, is measured perpendicularly to the bases. The term is used in various languages to mean trapezoidal, though definitions of trapezoid can vary by tradition: in some conventions a trapezoid is defined as having at least one pair of parallel sides (which would also include parallelograms); in others, a trapezoid has exactly one pair of parallel sides.

The area of a trapezoidale is A = (b1 + b2) * h / 2, where b1 and b2 are the lengths of the bases and h is the height. The length of the mid-segment, the line joining the midpoints of the legs and parallel to the bases, equals (b1 + b2) / 2. If the legs are equal, the figure is an isosceles trapezoidale; its diagonals are equal, and the base angles are equal.

In coordinate geometry, a trapezoidale can be defined by placing the bases on parallel lines and offsetting one base along the other. The trapezoidale appears in many practical contexts, including architectural profiles, ramps, and cross sections of truncated pyramids and wedges.

See also: trapezoid, trapezium, isosceles trapezoid.