[填空题]
The following diagram shows r35rm8r2,sq +nzie(-htiois three citi2fda wux)- a;wn/ic a7 g0qy0nes $\mathrm{A}$, $\mathrm{B}$ and $\mathrm{C}$ . City $\mathrm{B}$ is 70 $\mathrm{~km}$ from $\mathrm{A}$ , on a bearing of $130^{\circ}$ . City $ \mathrm{C}$ is 40 $\mathrm{~km} $ from City $\mathrm{B}$ , on bearing of $75^{\circ}$ .
1. Find CBA.
2. Find the distance from City A to C . ≈
3. If you wanted to travel from city A directly to City C, find the bearing you would need to travel. ≈
4. Find the area enclosed by connecting the three cities in a triangle ABC.