Which statement best describes a parallelogram?

Which statement best describes a parallelogram?

• A. A quadrilateral with four right angles.
• B. A quadrilateral with all sides congruent.
• C. A quadrilateral whose opposite sides are parallel and equal.
• D. A polygon with four sides and one pair of parallel sides.

Answer: (C)

Two pairs of opposite sides that are parallel and equal define a parallelogram. In such a shape, each pair of opposite sides runs in the same direction and has the same length, and the opposite angles are equal as a consequence. This is why the statement that opposite sides are parallel and equal best describes a parallelogram. Other shapes have different defining features: a quadrilateral with four right angles is a rectangle, not all parallelograms; a quadrilateral with all sides equal is a rhombus, which is a special parallelogram but not the defining feature itself; a polygon with four sides and one pair of parallel sides is a trapezoid, which does not have two pairs of parallel sides.

Two pairs of opposite sides that are parallel and equal define a parallelogram. In such a shape, each pair of opposite sides runs in the same direction and has the same length, and the opposite angles are equal as a consequence. This is why the statement that opposite sides are parallel and equal best describes a parallelogram.

Other shapes have different defining features: a quadrilateral with four right angles is a rectangle, not all parallelograms; a quadrilateral with all sides equal is a rhombus, which is a special parallelogram but not the defining feature itself; a polygon with four sides and one pair of parallel sides is a trapezoid, which does not have two pairs of parallel sides.