four (4)
A parallogram has two pairs of parallel sides. A trapezoid has one pair of parallel sides. A regular octagon has four pairs of parallel sides. An irregular octagon may have from 3 pair to no pair of parallel sides.
2 pairs of parallel lines
An octagon can have up to four pairs of parallel sides, but it need not have any.
1 pair of parallel line
It has a pair of opposite parallel lines of different lengths
A rhombus has 2 pairs of parallel lines.
A trapezoid has one pair of parallel sides. They are opposite parallel lines of different lengths.
Zero
Two.
2
1 pair of parallel lines
A trapezoid has 1 pair of opposite parallel lines of different lengths