Trapezoid/ˈtræpəzɔɪd/ Definition 1 of 3Pro Tip 1/3Mathematical Shape Trapezoid refers to a specific four-sided figure in math, important for geometry. Every trapezoid has two bases that are its parallel sides. Pro Tip 2/3Pair of Sides Not all sides of a trapezoid are parallel; only one pair is. Identify the parallel sides when you draw a trapezoid. Pro Tip 3/3Versatile Application Trapezoids are used in various fields, like architecture and design, due to their unique shape. The building's roof is shaped like a trapezoid.