Construct a square of side $3 \, cm$.

(N/A) Steps of construction:
$1.$ Draw a line segment $AB = 3 \, cm$.
$2.$ At point $A$,construct a perpendicular line $AY$ such that $\angle YAB = 90^{\circ}$.
$3.$ With $A$ as the centre and radius $= 3 \, cm$,draw an arc to intersect $AY$ at point $D$.
$4.$ With $B$ as the centre and radius $= 3 \, cm$,draw an arc above $B$.
$5.$ With $D$ as the centre and radius $= 3 \, cm$,draw another arc to intersect the previous arc at point $C$.
$6.$ Join $BC$ and $DC$. Thus,$ABCD$ is the required square of side $3 \, cm$.