Construct an angle of $30^{\circ}$.

(N/A) $(i)$ Angle of $30^{\circ}$
Steps of construction:
$I.$ Draw a ray $OA$.
$II.$ With $O$ as the center and a suitable radius,draw an arc,cutting $\overrightarrow{OA}$ at $B$.
$III.$ With $B$ as the center and the same radius,draw an arc to cut the previous arc at $C$.
$IV.$ Join $\overrightarrow{OC}$. Now,$\angle BOC = 60^{\circ}$.
$V.$ Draw the bisector of $\angle BOC$ to get ray $\overrightarrow{OD}$.
Thus,$\angle BOD = \frac{1}{2} \angle BOC = \frac{1}{2}(60^{\circ}) = 30^{\circ}$.
Therefore,$\angle BOD = 30^{\circ}$.