www.shmoop.com/quadrilaterals/trapezoids.html

A trapezoid is a quadrilateral with only one set of parallel sides. ... How many pairs of parallel lines do you see? The top and ... That means m∠1 = 107° as well.

study.com/academy/lesson/how-to-find-the-altitude-of-a-trapezoid.html

Oct 3, 2017 ... Isosceles Trapezoid: Definition, Properties & Formula .... Let's see how we can calculate the altitude of a trapezoid using an example: ...

www.freemathhelp.com/feliz-trapezoids.html

Definition and examples of a trapezoid. This geometry lesson explains that a trapezoid has four sides, with two of them being parallel.

artofproblemsolving.com/wiki/index.php?title=Trapezoid

Trapezoids are characterized by having one pair of parallel sides. In general it is probably safe to assume that "one pair" means ...

www.cambridgemaths.org/blogs/where-in-the-world-trapezoid-trapezium

Oct 3, 2017 ... Pupils rarely fully understand or know a true mathematical definition for ... to ask yourself is why do we have the inclusive definitions we do?

www.geom.uiuc.edu/~dwiggins/conj19.html

A trapezoid is a quadrilateral with exactly one pair of parallel sides. In a trapezoid the parallel sides are called bases. A pair of angles that share a base as a ...

www.varsitytutors.com/hotmath/hotmath_help/topics/quadrilaterals

A trapezoid is a quadrilateral with exactly one pair of parallel sides. ... say trapezium ; in America, trapezium usually means a quadrilateral with no parallel sides.

www.wyzant.com/resources/lessons/math/geometry/quadrilaterals/trapezoids_and_kites

Definition: A trapezoid is a quadrilateral with exactly one pair of parallel sides. ... If we forget to prove that one pair of opposite sides is not parallel, we do not ...

www.cliffsnotes.com/study-guides/geometry/polygons/properties-of-trapezoids

Recall that a trapezoid is a quadrilateral with only one pair of opposite sides parallel and that the parallel sides are called bases and the nonparallel sides.