A ray of light is incident at an angle of incidence 60^° on the glass slab of refractive index √ 3. After refraction, the light ray emerges out from…

A ray of light is incident at an angle of incidence $\displaystyle 60^{\circ}$ on the glass slab of refractive index $\displaystyle \sqrt{3}$. After refraction, the light ray emerges out from other parallel faces and lateral shift between incident ray and emergent ray is $\displaystyle 4 \sqrt{3} \mathrm{~cm}$. The thickness of the glass slab is \_\_\_\_ cm.