Since you described it as 2 sets of parallel sides, I'll assume you meant a 4 sided polygon(quadrilateral). This special case is called a rhombus.
A parallelogram.
Parallelogram
there are 2 sets of parallel lines in a square
A square has four sets of parallel lines.
A rectangle.
parallelogram
Since you described it as 2 sets of parallel sides, I'll assume you meant a 4 sided polygon(quadrilateral). This special case is called a rhombus.
When it has two sets of parallel lines
When it has two sets of parallel lines
A parallelogram.
Parallelogram
there are 2 sets of parallel lines in a square
A square has four sets of parallel lines.
Well a nonagon is a nine sided polygon. If you make the lines or sides parallel, then you will have a parallel figure. Or some parallel lines on a figure (polygon). If you choose to make your polygon (nonagon) have a pair of congruent sides, then your polygon will have some congruent sides. Therefore it really matters what your shape looks like. For example, a quadrilateral can be a square or a kite (or many others but I'm just using these) a kite might have no parallel lines and a square may have 2 sets of parallel lines. Do you get it? Does that answer your question? FYI: A nonagon is also known as a enneagon :)
When it has two sets of parallel lines
General term for a polygon with 4 sides is a quadrilateral. A parallelogram is the special case with two pairs of parallel sides.