trapezoid
trapezoids
It is impossible. You must have at least two sides which are parallel to one another.
All regular polygons with an even number of sides. Irregular polygons with an odd number of sides can have parallel sides. There are also non polygonal shapes that can have parallel sides.
Put 2 lines on the perpendicular sides and put 1 line for the parallel sides
Infinitely many. Every regular polygon with 2n sides has n pairs of parallel sides. Then there are irregular polygons which can have parallel sides. And there are also irregular shapes which have parallel sides.
You need at least one pair of parallel sides. Most trapezoids have that.
A trapezoid and an isosceles trapezoid
A shape with four or more sides can have two parallel sides.
There are no parallel sides on a nonagon (nine-sided figure)... Regular shapes with an odd-number of sides have no parallel sides.
Circles
Well If you are looking for a four sided shape with no parallel sides it is called a trapezium.
Not all four-sided shapes have one pair of parallel sides. For example, a rectangle and a trapezoid can have one pair of parallel sides, but a general quadrilateral does not necessarily have any parallel sides. Shapes like rhombuses and squares have two pairs of parallel sides, while irregular quadrilaterals may have none. Thus, the presence of parallel sides depends on the specific type of four-sided shape.