# right trapezoid

A right trapezoid is a trapezoid that has at least two right angles. Below is a picture of a right trapezoid.

In some dialects of English (e.g. (http://planetmath.org/Eg) British English), this figure is referred to as a right trapezium. Because of the modifier “right”, no confusion should arise with this usage.

All rectangles are right trapezoids (unless the definition of trapezoid is used, see the entry on trapezoid (http://planetmath.org/Trapezoid) for more details). Note also that, in Euclidean geometry, a trapezoid cannot have an odd number of right angles.

A is a trapezoid that is simultaneously a right trapezoid and an isosceles trapezoid. In Euclidean geometry, such trapezoids are automatically rectangles. In hyperbolic geometry, such trapezoids are automatically Saccheri quadrilaterals. Thus, the phrase “right isosceles trapezoid” occurs rarely.

Right trapezoids are used in the trapezoidal rule and composite trapezoidal rule for estimating Riemann integrals.

Title right trapezoid RightTrapezoid 2013-03-22 17:11:55 2013-03-22 17:11:55 Wkbj79 (1863) Wkbj79 (1863) 10 Wkbj79 (1863) Definition msc 51-00 right trapezium LambertQuadrilateral SaccheriQuadrilateral