Two ships are approaching a port along straight routes at constant speeds. Initially, the two ships and the port formed an equilateral triangle with sides of length $24 \mathrm{km}$. When the slower ship travelled $8 \mathrm{km}$, the triangle formed by the new positions of the two ships and the port became right-angled. When the faster ship reaches the port, the distance, in $\mathrm{km}$, between the other ship and the port will be
- $4$
- $6$
- $12$
- $8$