Here's the question you clicked on:
sk8erkid17
When constructing a perpendicular bisector, why must the compass opening be greater than one half the length of the segment?
if the distance is less than 1/2, the 2 circles don't intersect
because if the compass length is less than half the length of the segment the two arcs of the compass will never intersect
Try it for yourself and see.
the compass length does not NEED to be greater than one half the length of a segment. but by having it so, it takes less time to do it.