What is a four sided figure with all right angles but opposite sides equal and adjacent sides unequal?

A four-sided figure characterized by all right angles, with opposite sides that are equal while adjacent sides remain unequal is defined as a rectangle. In a rectangle, the lengths of opposite sides are equal, and all angles measure 90 degrees, fulfilling the criteria of having right angles.

In the context of this question, while a rhombus, trapezoid, and rhomboid have distinct definitions and properties, they do not satisfy all the conditions presented. A rhombus has all sides equal but does not necessarily have right angles. A trapezoid typically has only one pair of parallel sides and might not have right angles at all. A rhomboid has opposite sides equal as well, but its angles can vary, meaning it does not have to have right angles. Therefore, a rectangle is the only figure that perfectly matches the description of having four right angles, with opposite sides equal and adjacent sides unequal.