Construct a quadrilateral ABCD, where AB = 4.2 cm,

Steps of construction :

Step I : Draw $\mathrm{BC}=3.6 \mathrm{~cm}$.

Step II : Construct $\angle \mathrm{ABC}=30^{\circ}$ at B.

Step III : With B as the centre and radius $4.2 \mathrm{~cm}$, cut off BA $=4.2 \mathrm{~cm} .$

Step IV : Construct $\angle \mathrm{BCD}=150^{\circ}$ at C.

Step V : With C as the centre and radius $4.8 \mathrm{~cm}$, cut off $\mathrm{CD}=4.8 \mathrm{~cm} .$

Step VI : Join AD.

The quadrilateral so obtained is the required quadrilateral.