The perpendicular bisector is the perpendicular bisector.

The line that passes through the midpoint of a line segment and is perpendicular to the line segment is called the perpendicular bisector of the line segment.

The perpendicular bisector, or "median", is a very important part of junior high school geometry. A straight line that divides a line segment into two equal segments in the middle and is perpendicular to the segment is called the perpendicular bisector of the segment. Usually, a compass and ruler are used to draw it.

Let the coordinates of the two endpoints of the line segment be (x1,y1), (x2,y2)

Then the perpendicular bisector equation can be obtained by the fact that the distances from any point on the line to the two endpoints are equal:

(x-x1)^2+(y-y1)^2=(x-x2)^2+(y-y2)^2

2(x1-x2)x+2(y1-y2)y=x1^2+y1^2-x2^2-y2^2