Show me the steps to solve this truss using stiffness method for indeterminate structure.$$

QUESTION $3$

Figure Q$3$ is a plane truss $\backslash ($ A B C D $\backslash )$ having a pinned supported at $\backslash ($ B $\backslash )$ and $\backslash ($ D $\backslash ),$ while $\backslash ($ C $\backslash )$ is supported by roller. By using the Stiffness Method;

a$)$ establish the element stiffness matrices in global coordinate system. $($CO$1$:PO$2)($C$3)$

$(10$ marks$)$

b$)$ solve for the unknown degree of freedom. $($CO$2$:PO$2)($C$4)$

$(7$ marks$)$

c$)$ determine axial force in member AB if the temperature is increased by $\backslash (40^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ affecting all members. Assume the coefficient of thermal expansion equal to $\backslash (11\mathrm{.}5\backslash$times $10^\{-6\}/\{\}^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).($CO$2$:PO$2)($C$5)$

Take the axial rigidity, $\backslash ($ E A $\backslash ),$ is $300000$ kN for every member of the truss.

Figure Q$3$