Definition:Perpendicular Bisector

Let $$AB$$ be a line segment.

The perpendicular bisector of $$AB$$ is the straight line which:


 * is perpendicular to $$AB$$;


 * passes through the point which bisects $$AB$$.


 * PerpendicularBisector.png

It follows from the parallel postulate that, in Euclidean geometry, the perpendicular bisector for any given line segment is unique.