A parallelogram with four right angles.

A parallelogram with four right angles.

• A. Rectangle
• B. Square
• C. Rhombus
• D. Trapezoid

Answer: (A)

A parallelogram with four right angles is a rectangle. In a parallelogram, opposite angles are equal and consecutive angles are supplementary. If one angle is 90 degrees, the adjacent angles must also be 90 degrees, so all four angles are right angles. That combination—parallelogram plus four right angles—defines a rectangle. A square also fits, since it’s a rectangle with all sides equal, but the given description identifies the shape as a rectangle. A rhombus has equal sides but doesn’t require right angles, and a trapezoid has only one pair of parallel sides, so they don’t match the four right angles condition.

A parallelogram with four right angles is a rectangle. In a parallelogram, opposite angles are equal and consecutive angles are supplementary. If one angle is 90 degrees, the adjacent angles must also be 90 degrees, so all four angles are right angles. That combination—parallelogram plus four right angles—defines a rectangle. A square also fits, since it’s a rectangle with all sides equal, but the given description identifies the shape as a rectangle. A rhombus has equal sides but doesn’t require right angles, and a trapezoid has only one pair of parallel sides, so they don’t match the four right angles condition.