Calculate the support reaction$($s$)$ at $\backslash ($ A $\backslash )$ and then draw the free$-$body diagram of segment $\backslash ($ A B $\backslash )$ of the beam to determine the internal forces at $\backslash ($ B $\backslash ).$

Note: Apply equations of equilibrium to the entire beam to calculate support reactions. Then, make a section at B to determine internal forces.