Draw a rhombus whose side is 7.2 cm

Steps of construction:

Step1: Draw $A B=7.2 \mathrm{~cm}$

Step2: Draw $\angle A B Y=60^{\circ}$

$\angle B A X=120^{\circ}$

Sum of the adjacent angles is 180°

$\angle B A X+\angle A B Y=180^{\circ}$

$=>\angle B A X=180^{\circ}-60^{\circ}=120^{\circ}$

Step 3: 

Set off $A D(7.2 \mathrm{~cm})$ along $A X$ and $B C(7.2 \mathrm{~cm})$ along $B Y$.

Step 4: Join $C$ and $D$.

Then, ABCD is the required rhombus.