Read the following passage.

The square is probably the best known of the quadrilaterals. It is defined as having all sides equal. All its interior angles are right angles (90°). From this it follows that the opposite sides are also parallel. A square is simply a specific case of a regular polygon, in this case with 4 sides. All the facts and properties described for regular polygons apply to a square.

The rectangle, like the square, is one of the most commonly known quadrilaterals. It is defined as having all four interior angles 90° (right angles). The opposite sides of a rectangle are parallel and congruent.

A difference between a square and rectangle is that _______________.