## Review of Quadrilaterals

Read this chapter, which summarizes all properties of various quadrilaterals, including the properties of their diagonals.

### Quadrilaterals

The prefix "quad-" means "four", and "lateral" is derived from the Latin word for "side". So a quadrilateral is a four-sided polygon. Since it is a polygon, you know that it is a two-dimensional figure made up of straight sides. A quadrilateral also has four angles formed by its four sides.

, , and are the sides and , , and are the vertices of the quadrilaterals.

Line segments and joining two non-consecutive vertices are called diagonals.

Two sides like and having a common endpoint are called adjacent sides.

There are many common special quadrilaterals that you should be familiar with. Below, these special quadrilaterals are described with their definitions and some properties.

Source: CK-12, https://flexbooks.ck12.org/cbook/ck-12-interactive-geometry-for-ccss/section/1.5/primary/lesson/quadrilaterals-geo-ccss/