The rigid bar deflection at $\mathrm{B}$ can be related to the deformation in member $\left(1\right)$:

${\mathrm{v}}_{\mathrm{B}}={\mathrm{\delta }}_1$

Substitute and rearrange to develop an expression for the rigid bar deflection at $\mathrm{D}$:

${\mathrm{v}}_{\mathrm{D}}=\frac{1,640 \mathrm{mm}}{760 \mathrm{mm}}{\mathrm{\delta }}_1$