The document discusses the classification of quadrilaterals. It defines quadrilaterals as figures with four vertices, four sides, and four interior angles. It then classifies quadrilaterals into three categories: trapezoids which have one set of parallel sides; non-trapezoids which have no parallel sides; and parallelograms which have two sets of parallel sides. Several example quadrilaterals are provided and classified into these three categories through a series of multiple choice questions and answers.