A four-sided polygon with all sides congruent and with four right angles is a square.
no, because a polygon with four right angles is a rectangle
A right trapezoid is a four-sided polygon with two right angles and two parallel sides.
A square or a rectangle
A parallelogram is a four sided polygon with opposing parallel sides of equal length. Then if it has four right angles, the polygon becomes a rectangle.
Four equal sides and no right angles
A polygon with four sides and four angles is a quadrilateral.
A square has 4 right angles and 4 equal sides.