Joaquin is constructing the perpendicular bisector of line ab. what should be his first step?

When constructing perpendicular bisector, the following steps are followed;
i. Place the compass at one end of the segment
ii. Adjust the compass and draw the arcs above and below the line
iii. Draw the arcs from the other end of the line
iv. Place the ruler where the arcs  cross and draw the line segment