Question 19

Ship $A$ stops in the middle of the sea. The captain sees two other ships that also stop. Ship $C$ is aligned with ship $A$, while ship $B$ is perpendicular to $AC$. If the distance from ship $B$ to ship $C$ is $500\text{ meter}$ and the included angle between $AC$ and $BC$ is $60^\circ$, then the distance from ship $A$ to ship $B$ is ....