$3.$ For a frame in equilibrium shown in Figure $3,$ draw all free body diagrams $($FBDs$).$

$($LO $3\mathrm{.}4\mathrm{.}1)$

$\backslash ((20\backslash \%)\backslash )$

$($answer: $3$ sketches with load and geometry as shown and $\backslash (\backslash$mathrm$\{$x$\}-\backslash$mathrm$\{$y$\}\backslash )$ coordinate system,

$\backslash (\backslash$mathrm$\{$AC$\}$: $2\backslash )$ perpendicular forces and a moment at A

$2$ perpendicular force $($or one force along line CD $)$ at C

CD : $2$ perpendicular forces opposite to forces in FBD of AC $($or one force along line CD$)$ at C $2$ perpendicular force $($or one force along line CD $)$ at D

DB: $2$ perpendicular forces opposite to forces in FBD of CD $($or one force along line CD $)$ at D $2$ perpendicular force at $\backslash ($ B $\backslash ))$

Figure $3.$ Frame with fixed support at $\backslash ($ A $\backslash ),$ pinned joints at $\backslash ($ C $\backslash )$ and $\backslash ($ D $\backslash ),$ and pin support at $\backslash ($ B $\backslash ).$