They remain separated
By calculating the gradient of a given line, one can establish whether it is overlapping or not overlapping. Parallel lines do not overlap.
Any two non-overlapping circles.
draw two triangles with overlapping lines
no, if two lines are not parallel then the will eventually have to intersect.Alternate perspective:Yes, if two lines are non-parallel, they need not intersect in three dimensional space.
Non interesting lines are called lines
Are non-parallel lines.
Skew lines
No. You can have at most two vertices where an odd number of lines meet. The required figure has four.
Two non-parallel lines in a plane will intersect at exactly one point. This is because non-parallel lines have different slopes, which means they will eventually cross each other. If the lines were parallel, they would never meet. Thus, the intersection of two non-parallel lines is a unique point.
skewed lines
Non coplanar lines.
Ellipses and non-square rectangles have two lines of symmetry.