In geometry, a trapezoid in North American English, or trapezium (/trəˈpiːziəm/) in British English, is a quadrilateral that has one pair of parallel sides.
The parallel sides are called the bases of the trapezoid. The … See more

There is some disagreement whether parallelograms, which have two pairs of parallel sides, should be regarded as trapezoids.
Some define a … See more

A right trapezoid (also called right-angled trapezoid) has two adjacent right angles. Right trapezoids are used in the trapezoidal rule for estimating areas under a curve. See more

Given a convex quadrilateral, the following properties are equivalent, and each implies that the quadrilateral is a trapezoid:
• It has two adjacent angles that are supplementary, that is, they add up to 180 degrees See more

The ancient Greek mathematician Euclid defined five types of quadrilateral, of which four had two sets of parallel sides (known in English as square, rectangle, rhombus and rhomboid) and … See more

Four lengths a, c, b, d can constitute the consecutive sides of a non-parallelogram trapezoid with a and b parallel only when
$${\displaystyle \displaystyle |d-c|<|b-a|<d+c.}$$ See more

The midsegment (also called the median or midline) of a trapezoid is the segment that joins the midpoints of the legs. It is parallel to the bases. … See more