Can you help me understand $8\mathrm{.}6?$ Thanks :$)$

Problems $8\mathrm{.}6$ and $8\mathrm{.}7$

The structure shown consists of a single member ABCDE with a pin support at

A and a roller support at $E.$ Points $B$ and $D$ are at the midpoints of their

respective segments. Determine the internal forces acting on:

Problem $8\mathrm{.}6$

Cross sections $F,G,H,$ and I, which are located immediately to the right of $A,$

the left of $B,$ the right of $B,$ and the left of $C,$ respectively.

Problem $8\mathrm{.}7$

Cross sections $J,K,L,$ and $M,$ which are located immediately to the right of $C,$

the left of $D,$ the right of $D,$ and the left of $E,$ respectively.