Construct a quadrilateral ABCD in which BC = 4 cm,

Steps of construction:

Step I: Draw $\mathrm{BC}=4 \mathrm{~cm}$.

Step II: With B as the centre and radius $6.5 \mathrm{~cm}$, draw an arc.

Step III : With $\mathrm{C}$ as the centre and radius $5 \mathrm{~cm}$, draw an arc to intersect the arc drawn in Step II at D.

Step IV: With $\mathrm{C}$ as the centre and radius $5.6 \mathrm{~cm}$, draw an arc on the same side.

Step V : With D as the centre and radius $4.5 \mathrm{~cm}$, draw an arc to intersect the arc drawn in Step IV at A.

Step VI : Join BA, AC, DA, BD and CD to obtained the required quadrilateral.