Problem $4(20pts)$ : Trusses: Method of joints $-$ Practice. For the truss below:

$($i$)$ Calculate its determinacy $(2$ pts$)$

$($ii$)$ Generate the FBD $(3$ pts $)$

$($iii$)$ Solve for its reactions $(3$ pts$)$ and perform one validation $(3$ pts$)$

$($iv$)$ Find the forces in all its members using the Method of joints $(9$ pts$).$