On a map drawn to a scale of $1:50,000$, a rectangular plot of land $\mathrm{ABCD}$ has the following dimensions. $\mathrm{AB}=6\mathrm{cm};\mathrm{BC}=8\mathrm{cm}$ and all angles are right angles. Find:
(i) the actual length of the diagonal distance $\mathrm{AC}$ of the plot in $\mathrm{km}$.
(ii) the actual area of the plot in sq km.