Two lines cross or intersect at a point.
Parallel lines.
a segment
parallel lines
They are perpendicular lines
Two lines cross or intersect at a point.
The location two lines cross or intersect is called a vertex.
Parallel lines.
a segment
Lines that cross each other at 90 degrees are perpendicular lines.
"perpendicular"
parallel lines
They are perpendicular lines
the point of intersecting
Perpendicular
Mutually perpendicular.
They are called parallel lines, provided they remain the same distance from each other.