Two slabs with square cross section of different materials (1,2) with equal sides (l) and thickness d_1 and d_2 such that d_2=2 d_1 and l>d_2.…

Two slabs with square cross section of different materials $\displaystyle (1,2)$ with equal sides $\displaystyle (l)$ and thickness $\displaystyle d_1$ and $\displaystyle d_2$ such that $\displaystyle d_2=2 d_1$ and $\displaystyle l>d_2$. Considering lower edges of these slabs are fixed to the floor, we apply equal shearing force on the narrow faces. The angle of deformation is $\displaystyle \theta_2=2 \theta_1$. If the shear moduli of material $\displaystyle 1$ is $\displaystyle 4 \times 10^9 \mathrm{~N} / \mathrm{m}^2$, then shear moduli of material $\displaystyle 2$ is $\displaystyle x \times 10^9 \mathrm{~N} / \mathrm{m}^2$, where value of $\displaystyle x$ is $\displaystyle \_\_\_\_$.