Median is the line segment from the vertex to the midpoint of the opposite side. <em>Note that midpoint is the point that bisects the side thus creating two congruent (equal) line segments.</em>
Altitude is the line segment from the vertex forming a perpendicular (right angle) with the opposite side.
Angle bisector is the line segment that divides the vertex angle into two congruent (equal) angles.
Perpendicular bisector is the line segment from the midpoint of a side forming a perpendicular (right angle) with the opposite side.
