Next, substitute the force-deformation relationships into the geometry of deformation relationship:

$$\begin{gathered} \mathbf{ }\mathbf{Force}\mathbf{ }\mathbf{deformation}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{Geometry}\mathbf{ }\mathbf{deformation} \\ {\mathrm{\delta }}_1=\frac{{\mathrm{F}}_1{\mathrm{L}}_1}{{\mathrm{A}}_1{\mathrm{E}}_1} {\mathrm{\delta }}_2=\frac{{\mathrm{F}}_2{\mathrm{L}}_2}{{\mathrm{A}}_2{\mathrm{E}}_2} \frac{ {\mathrm{\delta }}_1}{380 \mathrm{mm}}=\frac{ {\mathrm{\delta }}_2 }{760 \mathrm{mm}} \\ \frac{{\mathrm{F}}_1{\mathrm{L}}_1}{{\mathrm{A}}_1{\mathrm{E}}_1} \frac{1}{380 \mathrm{mm}}=\frac{{\mathrm{F}}_2{\mathrm{L}}_2}{{\mathrm{A}}_2{\mathrm{E}}_2} \frac{1}{760 \mathrm{mm}} \end{gathered}$$