As you learned in the last chapter, quadrilaterals are four-sided poly-
gons. The interior of a quadrilateral contains two unique triangles, so the
sum of the interior angles of any quadrilateral is 360°. Quadrilaterals are a
unique family of polygons because there are so many distinct types of
quadrilaterals, such as squares, rectangles, parallelograms, and rhombuses.
What’s the difference between all of these types of quadrilaterals and how
are they classified? Quadrilaterals are divided into three major categories,
based on how many pairs of opposite parallel sides they have:
- The first group of quadrilaterals has no pairs of parallel sides.
These quadrilaterals do not have a special name.
D
CA B