A rhombus has diagonals perpendicular to each other.
1. Draw AC=6.3cm
2. Draw perpendicular bisector XY of AC intersecting AC at O.
3. Taking O as centre and 12×5.8=2.9cm as radius
draw two arcs intersecting OX and OY at B and D respectively.
4. Join AB, BC, CD and AD.
ABCD is the required rhombus.