Always, Sometimes, Never Quadrilaterals

A square is ______ a rectangle. (Always / Sometimes / Never)

Always. A square satisfies all properties of a rectangle because it has four right angles ($90^\circ$).

A rectangle is ______ a square. (Always / Sometimes / Never)

Sometimes. A rectangle is only a square when all four of its side lengths are equal.

A rhombus is ______ a square. (Always / Sometimes / Never)

Sometimes. A rhombus is only a square when all four of its interior angles measure $90^\circ$.

A trapezoid is ______ a parallelogram. (Always / Sometimes / Never)

Never. Under the standard inclusive/exclusive classification, a trapezoid has exactly one pair of parallel sides, whereas a parallelogram has two pairs.

A parallelogram is ______ a rhombus. (Always / Sometimes / Never)

Sometimes. A parallelogram is a rhombus only when all four of its sides are congruent.

A quadrilateral with diagonals that bisect each other is ______ a parallelogram. (Always / Sometimes / Never)

Always. Diagonals bisecting each other is a sufficient condition for a quadrilateral to be a parallelogram.