step by step explanation:
Draw a perpendicular line AB=6cm
Open your compass to a radius of 4.5cm and place it on B to construct an arc
Again open your compass to a radius of 5.9cm and step at A and draw an arc to intersect the first one at C
Open your compass to a reasonable radius and step at A and B to construct an arc
With the same radius step at B and C to construct another arc
Draw a line to bisect the arcs