The given square ABCD can be drawn as follows:

Step 1: Draw a line segment AB = 6.4 cm.

Step 2: Draw BE perpendicular to AB

Step 3: With 6.4 cm from B draw an arc cutting BE at C

Step 4: With 6.4 cm from A draw an arc

Step 5: From C take radius of 6.4 cm and cut the arc drawn in step 4 and the point of intersection is D.

Step 6: Now, join CD and AD.

ABCD is the required square.