Question

a line 4.4 cm and draw its perpendicular bisector

Answer 1

name the line as AB.
now take a convenient radius and draw an arc with A as centre.This arc should be drawn up as well as down.now with B as centre draw an arc cutting previous arcs at M and N. Join MN. thus it is your perpendicular bisector.
Note:-The convnient radius should be more than the half of the line.And in the entire process the radius should be same.

Answer 2

From the end of points of any radius draw perpendicular bisector