Which geometric figure is NOT necessarily a square nor a rectangle, with opposite angles equal and opposite sides equal and parallel?

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

Answer: (A)

Opposite sides parallel and equal, with opposite angles equal, describe a parallelogram. This shape can be slanted, so it doesn’t have to be a square or a rectangle. A square is a special parallelogram with all sides equal and all angles right, and a rectangle is a parallelogram with right angles. A rhombus is another special parallelogram with all sides equal, not necessarily right angles. A trapezoid typically has only one pair of parallel sides, so it doesn’t fit the requirement of both opposite sides being parallel. So the figure that fits the given description and isn’t necessarily a square or a rectangle is a parallelogram.