$8\mathrm{.}11-8\mathrm{.}14.$ Use the unit$-$dummy$-$displacement method to analyze the

structures shown. In each case, assume that the cross$-$sectional areas of

all truss bars are $1$ sq in $.$ and that the material is linearly elastic with

$E={10}^7\mathrm{.}8\mathrm{.}11-8\mathrm{.}14.$ Use the unit$-$dummy$-$displacement method to analyze the structures shown. In each case, assume that the cross$-$sectional areas of all truss bars are $1$ sq in$.$ and that the material is linearly elastic with E$=10^(7)$psi$.$ Fig. P$\mathrm{.}8\mathrm{.}11$