[填空题]
The following diagramg4 3fss m/2o+o, ftlqgxul t:xzx4c/j4y8mc2w3 hky8 shows triangle ABC and sector ACD of a circle with centre C4 uhz :3xct wmjxl8 c8y/42kxy.
$\mathrm{AC}=5 \mathrm{~cm}, \mathrm{BC}=8 \mathrm{~cm} $, the area of triangle $\mathrm{ABC}=10 \sqrt{3} \mathrm{~cm}^{2}$ .
1. Find AĈB.
2. Find the exact area of sector ACD.
