One
only 1
A square has 2 pairs of opposite parallel lines.
There cannot be parallel lines in any [plane] triangles.
there are 2 sets of parallel lines in a square
There are 2 horizontal parallel lines in the letter Z
One
2
A triangle can have no parallel lines.
2
it has too parallel lines!
A pentagon has no parallel lines.
A cone does not have any parallel lines
only 1
It has two. One on the top and one through the middle.
how many sets of parallel lines are in a triangle
A square has 2 pairs of opposite parallel lines.