Which statement describes a trapezoid?

• A. A closed four-sided figure with both pairs of opposite sides parallel.
• B. A circle with four sides.
• C. A polygon having three sides.
• D. A closed four-sided figure in which only one pair of the opposite sides are parallel.

Answer: (D)

The main idea is that a trapezoid is a four-sided figure with exactly one pair of parallel sides. The statement that describes this is the one that says the figure is closed and has four sides, with only one pair of opposite sides parallel. This captures the defining feature: there is a single parallel pair (the bases), while the other pair are not parallel, distinguishing it from a parallelogram which has two pairs of parallel sides. It also rules out a triangle (three sides) and anything described as a circle or four-sided circle, which aren’t valid polygons. A helpful image is a shape with a top edge and bottom edge running parallel, with the side edges slanting so they aren’t parallel to each other.