A document defines and compares different types of quadrilaterals:
- A square has four equal sides and four right angles. Its diagonals are congruent and bisect each other.
- A rectangle has four right angles and opposite sides that are parallel and congruent. Like a square, its diagonals are congruent and bisect each other.
- A parallelogram has two pairs of parallel opposite sides. Its diagonals bisect each other and opposite angles are congruent.