Answer:
To perpendicular bisector of line segment WX. There are following steps:
1) Draw arcs or circles from points A and B on the both sides of WX.
2) Mark the intersection points as A and B.
3) Use the straightedge to draw a line through points W and X.
4) Name the intersection point as O on line segment WX.
Hence we have construct perpendicular bisector AB of WX which bisects at O.