All vertical lines are perpendicular to each other. true or false

Answer 1

This statement is FALSE.

However, it is true that all vertical lines are PARALLEL to each other.

Perpendicular lines (or line segments) that intersect will be at an angle of 90-degrees to one another, by definition; this is the meaning of the term "perpendicular".

Parallel lines never intersect at all, by definition; this is the meaning of the term "parallel".