2 pairs, the sides opposite each other are congruent to each other
Infinitely many.
2 pairs
A rectangle has two pairs of parallel and congruent sides. An equilateral rectangle, or square, has four equal sides. Other quadrilaterals include trapezoids, which have two adjacent and equal sides, parallelograms, which have two pairs of parallel and congruent sides, and rhombi, which have four equal sides. (The a rectangle is a type of parallelogram. What differentiates it is angle configuration. A rhombus is likewise differentiated from a square by angle configuration.)
One pair
A parallelogram has two pairs of congruent sides.
2 pairs, the sides opposite each other are congruent to each other
Infinitely many.
In a rhombus, all of the sides are congruent, so 4.
Opposite sides of a parallelogram are congruent and so it has 2 pairs of congruent sides.
A trapezoid may have zero or one pair of congruent sides.
2 pairs
2
A rectangle has two pairs of parallel and congruent sides. An equilateral rectangle, or square, has four equal sides. Other quadrilaterals include trapezoids, which have two adjacent and equal sides, parallelograms, which have two pairs of parallel and congruent sides, and rhombi, which have four equal sides. (The a rectangle is a type of parallelogram. What differentiates it is angle configuration. A rhombus is likewise differentiated from a square by angle configuration.)
2
Two pairs.
One pair