In triangle ABC, BD can be a median, an altitude, and a perpendicular bisector depending on its properties.
A median of a triangle is a line segment that connects a vertex to the midpoint of the opposite side.
In triangle ABC, if BD is a line segment that connects vertex B to the midpoint of side AC, then BD is a median.
An altitude of a triangle is a line segment that is perpendicular to a side and passes through the opposite vertex.
So, if BD is perpendicular to AC and passes through vertex B, then BD is an altitude.
A perpendicular bisector of a triangle is a line or line segment that divides a side into two equal parts and is perpendicular to that side.
If BD divides side AC into two equal parts and is perpendicular to AC, then BD is a perpendicular bisector.