Rod $\left(2\right)$ is assumed to be perfectly attached to the rigid bar; therefore, the change in length of rod $\left(2\right)$ must be $1.40 \mathrm{mm}$. From the rotated position of the rigid bar, it is evident that rod $\left(2\right)$ will grow shorter if rod $\left(1\right)$ grows longer. Therefore, the deformation of rod $\left(2\right)$ can be expressed as

${\mathrm{\delta }}_2=-1.40 \mathrm{mm}$

where the negative sign indicates contraction.