A four-sided polygon with opposite sides parallel and all sides congruent is a square.
A square or a rhombus
A square is a four-sided polygon with two congruent parallel sides.
A square's opposite sides are parallel and all the sides are congruent.
Yes opposite sides are parallel and congruent
A four-sided polygon with opposite sides parallel and all sides congruent is a square.
Any polygon with an even number of sides can have opposite sides that are congruent and parallel.
a trapezoid
Any polygon with 2n sides (n integer) where opposite sides are parallel, will have its opposite angles congruent.
A rectangle is a quadrilateral with opposite sides parallel and congruent and four right angles. If all four sides are congruent, it is a square.
A rectangle is a quadrilateral with opposite sides parallel and congruent and four right angles. If all four sides are congruent, it is a square.
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.
A square or a rhombus
It cannot be a quadrilateral because if one pair of opposite sides are congruent and parallel, it is a parallelogram and so the other two sides are also (mutually) congruent and parallel. Any polygon with 5 or more sides will have an irregular form which satisfies these conditions.
No
There are many such shapes. Any polygon with an even number of sides can have opposite sides that meet the above requirements.
A square is a four-sided polygon with two congruent parallel sides.