Draw a line segment of length 12.8 cm. Using compasses, divide it into four equal parts. Verify by actual measurement.

Step I: Draw a line segment $\overline{AB}$ = 12.8 cm

Step II: With centre A and B and a radius more than half of AB, draw two arcs that meet each other at D and L.
Step III: Join D and L which meets $\overline{AB}$ at E which is the midpoint of $\overline{AB}$.
Step IV: With centre A and E and a radius more than half of AE, draw two arcs that meet each other at F and G.
Step V: Join F and G which meets $\overline{AB}$ at H which is the midpoint of $\overline{AE}$.
Step VI: With centre E and B and a radius of more than half of EB, draw two arcs that meet each other at J and I.
Step VII: Join J and I which meets $\overline{EB}$ at K which is the midpoint of $\overline{EB}$ .
Therefore, on measuring, we find:
$\overline{AH}$ = $\overline{HE}$ = $\overline{EK}$ = $\overline{KB}$ = 3.2 cm.