Exercise $3$: For the bar assemblages shown as follows, determine $($a$)$ the nodal displacements, $($b$)$ the forces in each element, and $($c$)$ the reactions. You will call your function generated in Exercise $2$ and assemble the global matrix, modify$/$apply boundary conditions to the global matrix equations, and then find the solutions in MATLAB. For this Exercise, $E=210$GPa,$A_1=3{10}^{-4}{m}^2,A_2=A_3=A_4=2{10}^{-4}{m}^2$