A Quadrilateral has four-sides, it is 2-dimensional (a flat shape), closed (the lines join up), and has straight sides.
Properties:
Four sides (edges)
Four vertices (corners)
The interior angles add up to 360 degrees
Types of quadrilaterals:
Parallelogram, Rectangle, Rhombus,Square, Trapezoid, and Kite
I hope this answered your question. :D