In geometry, what is the term for a segment that bisects an angle?

The segment that bisects an angle is called an angle bisector. This term specifically refers to a ray or line segment that divides an angle into two equal smaller angles. For instance, if you have an angle measuring 60 degrees, the angle bisector would split it into two angles of 30 degrees each. This property of dividing the angle equally is what distinguishes an angle bisector from other types of segments.

In contrast, a median relates to triangles, connecting a vertex to the midpoint of the opposite side. An altitude refers to a segment from a vertex perpendicular to the opposite side, which has a different purpose in geometric constructions. A perpendicular bisector, similarly, involves dividing a segment into two equal parts at a right angle rather than bisecting an angle. Therefore, angle bisector is the correct and precise term for a segment that bisects an angle.