$(3)$ The steel framework is used to support the $2$ in thick lightweight concrete floor fill. This floor system will be used for an office building. Sketch the loading that acts along members BE and FED $($draw their FBD$).$ Set $a=6ft$ and $b=20ft.$

$(4)$ Repeat $(3)$ with $a=10ft$ and $b=20ft.$

Total weight of the concrete: $16$lb$/$ft$^2$ Office load: $50$lb$/$ft$^2$