A trapezoid has a pair of opposite parallel lines of different lengths A square has 2 pairs of opposite parallel lines of equal lengths A triangle has no parallel lines
A triangle has no parallel lines
There can be only one pair of perpendicular lines in an isosceles triangle when it is a right angled isosceles triangle. A non right angled isosceles triangle has no pairs of perpendicular lines.
A square has 2 pairs of equal opposite parallel lines
There are absolutely 0 parallel lines in any given triangle.
A square has 2 pairs of opposite parallel lines.
A triangle can never have any parallel sides.