The forward-backward angular asymmetry of the lepton pair in $\mathit{B}$ $\to$ ${\mathit{K}}^{(\ast )}{\ell }^{+}{\ell }^{-}$ ( $\mathit{B}$ $\to$ $\mathit{K}$ $/$ $\pi {\mathit{h}}^{+}{\mathit{h}}^{-}$) decay is defined as
A${}_{FB}$(s) = $\frac{N(cos\theta >0)-N(cos\theta <0)}{N(cos\theta >0)+N(cos\theta <0)}$,
where s=q${}^2/{{\mathit{m}}^2}_{\mathit{B}}$, and $\theta$ is the angle of the ${\ell }^{-}$ (${\mathit{h}}^{-}$) with respect to the flight direction of the $\mathit{B}$ meson, measured in the dilepton (dihadron) rest frame. In addition, the fraction of longitudinal polarization F${}_L$ of the ${\mathit{K}}^{\ast }$ and F${}_S$, the relative contribution from scalar and pseudoscalar penguin amplitudes in $\mathit{B}$ $\to$ $\mathit{K}{\ell }^{+}{\ell }^{-}$, can be measured from the angular distribution of its decay products.