$($a$)$ Write the equilibrium equation.

$($b$)$ Define the compatibility equation.

$($c$)$ Determine the torques at each support $?,T_C=?)$

$($d$)$ Evaluate the maximum shear stress in each segment $?,{}_{\text{m}\text{a}\text{x}}^{BC}=?)$

$($e$)$ compute the angle of twist of $?)$

$d_o^{AB}=d_o^{BC}=60mm$

$d_i^{AB}=30mm$

$G=26$GPa

$L_{AB}=400mm$

$L_{BC}=800mm$