For a line segment with endpoints (X1,Y1) and (X2,Y2), the midpoint of the line is ([(X1+X2)/2],[(Y1+Y2)/2]). If the line is parallel to the X axis, the Y coordinate is the same as the Y coordinate of the endpoint. If the line is parallel to the Y axis, the X coordinate is the same as the X coordinate of the endpoint.
While a line segment has only one midpoint, it has an infinite number of bisectors. Bisectors are lines or line segments that pass through the midpoint of the line.Learn more about Geometry