Quadrilaterals that have parallel opposite sides (assuming that each side is parallel to its opposite):
A parallelogram
A rectangle
A square (really a rectangle with all sides equal in length)
The Opposite Sides Parallel and Congruent Theorem states that if a quadrilateral has a pair of opposite sides that are parallel and congruent, then the quadrilateral is a parallelogram.
Then, the opposite sides are congruent.
A quadrilateral is a polygon with four sides. A parallelogram is a quadrilateral in which the opposite sides are parallel.
The opposite sides of a parallelogram are parallel lines and a parallelogram is a 4 sided quadrilateral
A trapezoid is a type of quadrilateral that does not have two pairs of opposite sides that are parallel. Instead, it has only one pair of opposite sides that are parallel, while the other pair is not. This distinguishes trapezoids from parallelograms, rectangles, and squares, which do have both pairs of opposite sides parallel.
The Opposite Sides Parallel and Congruent Theorem states that if a quadrilateral has a pair of opposite sides that are parallel and congruent, then the quadrilateral is a parallelogram.
If it doesn't have parallel sides, it's just classified as a quadrilateral.
I would be seriously concerned if a quadrilateral had more than two pairs of opposite sides parallel! A quadrilateral with two pairs of opposite sides parallel is a parallelogram.
Then, the opposite sides are congruent.
A Trapezium (can have two opposite sides parallel)A kite has no parallel opposite sides
parellelagram
A quadrilateral is a polygon with four sides. A parallelogram is a quadrilateral in which the opposite sides are parallel.
A square's opposite sides are parallel and all the sides are congruent.
Parallelogram
that quadrilateral would be called a trapezoid. :)
Only if it is a trapezoid (US usage) with one set of parallel sides, or a parallelogram with both sets of opposite sides parallel. The term quadrilateral only means that the shape has 4 sides.
A parallelogram is a quadrilateral with opposite sides that are parallel.