Either a square or a rectangle
rectangle, square
a square or a rectangle
A rectangle or a square.
That is called a rectangle.
It is a square or a rectangle where each interior angle is a right angle of 90 degrees.
A square or a rectangle
A quadrilateral with all right angles is a rectangle.
A rectangle, or perhaps a square.
A square or a rectangle
rectangle
A rectangle, or could be a square if lengths are the same.
A regular quadrilateral is a square and each angle is 90 degrees (i.e. a right angle).