Which shape is defined as a parallelogram with four right angles and four equal sides?

A shape defined as a parallelogram with four right angles and four equal sides is indeed a square. To clarify, a square meets all the criteria of a parallelogram, meaning it has opposite sides that are equal and parallel. The key characteristics that distinguish a square are that all four angles are right angles (90 degrees) and all four sides are of equal length.

This definition highlights how a square is a special type of both a rectangle (which has right angles but not necessarily equal sides) and a rhombus (which has equal sides but not necessarily right angles). Therefore, while a rectangle and a rhombus have their own properties, they do not satisfy both conditions of having equal sides and right angles simultaneously like a square does. A trapezoid, on the other hand, does not have two pairs of parallel sides and does not fit the criteria of being a parallelogram at all. Thus, the correct identification of this shape as a square stems from its specific properties of equality in side length and angle measures.