Show me the steps to solve $(25\%)$ The free body diagram $($F:B$.$D$.)$ of a two$-$hinged $($hinges in $x,Y$:$(0,0)$ and $(8,0))$ structural system is shown.

$($i$)$ Draw the force polygon and the funicular polygon $($flow of forces$)$ of the system.

$($ii$)$ Determine the coordinates $(x,Y)$ of the inflection points of the structural system.

$($iii$)$ Chose an equivalent system $($will have the same internal forces$),$ that it will not be affected $($no additional stresses$)$ in the case of support settlement.