Accounting for the clearance in the connections at $\mathrm{A}$ and $\mathrm{C}$, the elongation of rods $\left(2\right)$ is shown to be $1.3 \mathrm{mm}$.

The normal strain in rods $\left(2\right)$ can now be computed:

$$\begin{gathered} {\mathrm{\epsilon }}_2=\frac{{\mathrm{\delta }}_2}{{\mathrm{L}}_2} \\ =\frac{1.3 \mathrm{mm}}{900 \mathrm{mm}} \\ =0.001444 \mathrm{mm}/\mathrm{mm} \\ =\mathbf{1}\mathbf{,}\mathbf{444}\mathbf{ }\mathbf{\mu \epsilon } \end{gathered}$$

 

Finished