squares
a quadrilateral shape, is a shape with 4 sides. i.e a square
Anything without four sides, since a quadrilateral is a polygon with all four sides. An example of a shape not a quadrilateral would be a triangle.
It is any shape that has 4 sides. It can be a square, a parallelogram, a trapezoid, etc.
Rhombuses, rectangles, kites, parallelograms, and trapezoids are all irregular quadrilaterals.