It is an asymptote.
An angle bisector.
bisector
angle bisector
Such a ray is called a "bisector" of the angle.
Bisector.
A bisector.
You are drawing a line which divides the angle into 2 equal parts (halves).
if u divide it into 2 equal parts its a half
180
bisector
90 degree bisector
Nothing since there is no such word. However, an angle bisector is a line segment that divides an angle into two equal parts.