It's called a perpendicular bisector of the line segment.
Perpendicular lines or line segments intersect to form a right or 90 degree angle.
How am i supposed to kow this??? I am in second grade!
no, not here you can only type on here but they're two lines that cross you can ask somebody around you
Set a compass to draw a circle with a radius that's more than half the length of the line segment but less than the whole length. Put the compass point at one end of the segment and draw an arc above...