Learn about the parts of a quadrilateral, with definitions and diagrams, in this short video.
The size of the surface covered by a quadrilateral is called its area.
Each of the line segments that form the quadrilateral’s boundaries is called a side. A quadrilateral has four sides.
The total length of the four sides is called the perimeter.
The point where two sides meet is called a vertex. A quadrilateral has four vertices.
An imaginary line joining two opposite vertices is called a diagonal.
The angle formed by two adjacent sides is called an interior angle (or, simply, an angle). A quadrilateral has four angles.
The side upon which the quadrilateral is resting is called its base.
The length of a perpendicular line from the base to the side opposite the base is called the height.
Can you now identify the parts of a quadrilateral? Reinforce your learning with the worksheet below.
Note on the Worksheets
You can reduce the size of the worksheet by zooming out your browser screen. For Windows users, scroll down the mouse wheel while pressing the Ctrl key in your keyboard.