It can have 0, 1 or 2 pairs of parallel lines.
A pentagon can have 0, 1 or 2 pairs of parallel lines. It can have 0 to 4 lines perpendicular to an adjacent line. A rhombus must have two pairs of parallel lines and none of them may be perpendicular to any other.
There cannot be parallel lines in any [plane] triangles.
There are absolutely 0 parallel lines in any given triangle.
You can have 0, 1, 2, or 3 pairs of parallel sides in a heptagon.
0 pairs
It can have 0, 1 or 2 pairs of parallel lines.
A pentagon can have 0, 1 or 2 pairs of parallel lines. It can have 0 to 4 lines perpendicular to an adjacent line. A rhombus must have two pairs of parallel lines and none of them may be perpendicular to any other.
There cannot be parallel lines in any [plane] triangles.
There are absolutely 0 parallel lines in any given triangle.
Three pairs and one triplet. The triplet can be considered three pairs.
An isosceles triangle has no parallel sides but it does have 2 sides of equal lengths
A pentagon may have 0, 2, or 4 parallel lines. A regular pentagon has 0 parallel lines. A pentagon like a house has 2 parallel lines. A rectangle with a corner cut off has 4 parallel lines.
You can have 0, 1, 2, or 3 pairs of parallel sides in a heptagon.
There are 0 parallel lines that a triangle has.
A cone does not have any parallel lines
It can have anywhere between 0 and 12 pairs of parallel sides.