A$.)$Evaluate the determinacy and stability of the structure. Solve for the reactionary forces at C and D using global equilibrium.

B$.)$Determine the internal axial functions for each member attributable to the real loading.

C$.)$In order to calculate the vertical displacement at A using the principle of virtual work, determine the internal axial functions for each member attributable to the virtual loading.

D$.)$Calculate the vertical displacement at A using the principle of virtual work. Take A $=400$ mm$2$ and E $=200$ GPa for each member.