Draw a square with diagonal 6 cm ????????
Diagonals of a square bisect each other at 90ยบ. So draw a line segment which is of 6 cm length. Then draw another line segment which is the perpendicukar bisector of this one and extend it to 3 cm on each side making a total of 6 cm
This is because both diagonals are perpendicular bisectors of each other. Now join their end points and you have your square.