An example of a quadrilateral is a rectangle.
An example of something quadrilateral is a square.
Legnago is one of the famous Quadrilateral fortresses.
In shape it is quadrilateral with a cape-like prolongation into Belgium on the north.
It has the form of a quadrilateral, elongated from N.W.
The figures considered in § 22 are particular cases of the trapezium, which is a quadrilateral with two parallel sides.
Let ABCD be any quadrilateral formed of jointed links.