A ray that begins at the vertex of an angle and divides the angle into two equal angles is called

• A. Perpendicular Bisector
• B. Angle Bisector
• C. Segment Bisector
• D. Angle Median

Answer: (B)

An angle is split into two equal parts by a ray that starts at the vertex. This special ray is called the angle bisector. It precisely divides the angle so that the left and right angles have equal measure, which is the defining property.

A handy fact about the angle bisector is that any point on it is the same distance from the two sides of the angle, which helps visualize why it sits exactly in the middle.

Why the other terms don’t fit: a perpendicular bisector refers to a line that cuts a segment in half and is perpendicular to that segment, not about splitting an angle. A segment bisector cuts a segment in half, not an angle. An angle median isn’t a standard way to describe a line that halves an angle, and in the usual geometric sense it would imply a different construction that doesn’t guarantee equal angles at the vertex.