2
Only one.
one
Exactly one. No more, no less.
Since there is no such word as "perpindicuar", it is difficult to be sure. A line segment can have only one perpendicular bisector.
Equilateral triangles have 3 perpendicular bisectors
1
3
medians-3 altitudes-3
All bisectors intersect the line segment at the midpoint. There can be multiple bisectors, intersecting at the midpoint at different angles, but they all intersect the line segment at its midpoint. The midpoint separates the line segment into two equal halves.
One ! The word 'bisect' means to cut in two !
A bisector is a line (or line segment) which passes through the midpoint. You can have multiple lines intersect at this one point, and all of them will bisect the original line segment, since they pass through its midpoint. A perpendicular bisector passes through the midpoint, and also is perpendicular to the original line segment, so there will be only one of those.
Explain why a line segment can have one midpoint but many bisectors