An obtuse angle bisector refers to a line or ray that divides an obtuse angle into two equal angles. Here's a breakdown:

• Obtuse Angle: An obtuse angle is an angle that measures greater than 90 degrees and less than 180 degrees.
• Angle Bisector: An angle bisector is a line or ray that divides an angle into two congruent (equal) angles.

Therefore, when you bisect an obtuse angle, you are creating two acute angles (angles less than 90 degrees).

For example, if you have an obtuse angle of 120 degrees, its bisector will divide it into two angles of 60 degrees each.