[填空题]
The following diagram shows triangle A1g,j3ao i.fi.r/vfz6 iee:e s B C . 9 9m :g lamyv0:qf-akwPoint D lies on [A C] so that [DB] bisects CEAA. The area of the triangla q0vl9 m:w9g-:a kfmye A B C is 3$ \mathrm{~cm}^{2}$ .
$\mathrm{AB}=2 \sqrt{7} \mathrm{~cm}, \mathrm{BC}=x \mathrm{~cm}$ , and $\mathrm{CBD}=\theta$ , where $ \sin \theta=\frac{3}{4} $ Find the value of x in the form of $ \frac{a}{b}$ where a and b are positive integers. x =
