It is the perpendicular bisector
There is no name for it except "A line perpendicular to a line segment and passing through its midpoint".
A bisector is a line (or line segment) which passes through the midpoint. You can have multiple lines intersect at this one point, and all of them will bisect the original line segment, since they pass through its midpoint. A perpendicular bisector passes through the midpoint, and also is perpendicular to the original line segment, so there will be only one of those.
A midpoint is a point. It's the point exactly halfway between the endsof a line segment.A perpendicular bisector is a line. It's the line that passes through themidpoint of the segment, and is perpendicular to the segment.
Those would be perpendicular bisectors. If you do that to each side of the triangle they all meet at what is called the circumcenter. http://mathworld.wolfram.com/Circumcircle.html
It is the perpendicular bisector
A line that is perpendicular to the segment of a plane and passes through the midpoint.
There is no name for it except "A line perpendicular to a line segment and passing through its midpoint".
The perpendicular bisector of a line segment AB is the straight line perpendicular to AB through the midpoint of AB.
a line that intersects an edge of a triangle that is perpendicular to it and passes through the midpoint
A bisector is a line (or line segment) which passes through the midpoint. You can have multiple lines intersect at this one point, and all of them will bisect the original line segment, since they pass through its midpoint. A perpendicular bisector passes through the midpoint, and also is perpendicular to the original line segment, so there will be only one of those.
A midpoint is a point. It's the point exactly halfway between the endsof a line segment.A perpendicular bisector is a line. It's the line that passes through themidpoint of the segment, and is perpendicular to the segment.
A median of a triangle is a line segment joining a vertex to the midpoint of the opposite side. Altitude of a triangle is a straight line through a vertex and perpendicular to the opposite side or an extension of the opposite side.
Those would be perpendicular bisectors. If you do that to each side of the triangle they all meet at what is called the circumcenter. http://mathworld.wolfram.com/Circumcircle.html
The segment that passes through a vertex and is perpendicular to the opposite side is called the altitude of the triangle.
and is perpendicular to the opposite side.
Finding the midpoint of a segment Drawing a perpendicular line segment from a given point to a given segment Drawing a perpendicular line segment through a given point on a given segment Drawing a line through a given point parallel to a given line