Ohio Assessments for Educators (OAE) Mathematics Practice Exam

A trapezoid is defined specifically as a quadrilateral that has at least one pair of opposite sides that are parallel. This characteristic distinguishes trapezoids from other types of quadrilaterals. Having one pair of parallel sides is the defining trait of a trapezoid, which may also possess various angle relationships and side lengths, but the parallel sides are the primary focus of its definition.

In contrast, a quadrilateral with all sides equal refers to a rhombus, while a quadrilateral with two pairs of parallel sides describes a parallelogram or a rectangle, both of which are different from a trapezoid. The definition involving unequal angles does not accurately capture the essence of any specific category of quadrilaterals; trapezoids, in fact, can have equal or unequal angles depending on their specific type (e.g., isosceles trapezoid). The option that describes a quadrilateral with one pair of parallel sides is the only one that aligns with the standard geometric definition of a trapezoid.