The figure shown below is associated with Problem $2-25$ in Structural Analysis, $11$

th edition by Hibbeler. There is a pin support at A and rollers at B$,$ C$,$ and D$.$ The members are connected by hinges $($or pins$)$ at E and F$.$ Use equilibrium equations to construct the influence lines for the vertical reactions at B$,$ C$,$ and D$.$ For your downward direction and use the sign convention that an upward reaction force $$ is positive. Identify the ordinate values on the $3$ influence diagrams at A$,$ B$,$ C$,$ D$,$E and F$.$