frength of Materials$-$ENG GEN $241$

Problem $3[30$ pts $].$ Now lets modify our "Olympic" bar from Problem $2$ but this time, the bronze and silver are rectangular bars and gold remains a circular rod. Now, a total of two $(2)$ external forces are applied at B and C$.$ The composite bar is still fixed at points A and D$.$ Some materials properties where $.$ G is shear modulus and E is Modulus of Elasticity: $G_{\text{s}\text{i}\text{l}\text{v}\text{e}\text{r}}=28$GPa,$E_{\text{s}\text{i}\text{l}\text{v}\text{e}\text{r}}=69$GPa,$G_{\text{b}\text{r}\text{o}\text{n}\text{z}\text{e}}=37$GPa $E_{\text{b}\text{r}\text{o}\text{n}\text{z}\text{e}}=93$GPa,$G_{\text{g}\text{o}\text{l}\text{d}}=27GPa{E}_{\text{g}\text{o}\text{l}\text{d}}=79$GPa

$($a$)$ Calculate the reactions at the wall support at pt$.$ A and pt$.$ D$.$

$($b$)$ Calculate the displacement of point $B({}_B)$ only.