Quadrilaterals are polygons with four sides.
The interior (inside) angles of ALL quadrilaterals add up to 360o.
The exterior (outside) angles of ALL quadrilaterals (and all other polygons) add up to 360o as well!
a + b + c + d = 360o
Types of Quadrilaterals
Here are six types of quadrilaterals with special features.
Click on each one to find out more: