$3/3$ A carpenter holds a $12-$lb $2-$in$.$ by $4-in.$ board as shown. If he exerts vertical forces on the

board, determine the forces at A and B $.$

Note: This is an equilibrium problem, make sure you start with a proper Free Body Diagram $($FBD$)$

$-$in this case, of the board. Remove the guy from the picture and replace the hands with the force

vectors as indicated in the directions $($these are the support reactions in this case$).$ There are only $2$

unknowns in this problem, so you should only need two equilibrium conditions.