Loads are typically combined on structures using load factors, which take

into account the likelihood of different types of loads acting on a structure

simultaneously. A common controlling load combination is given as

follows:

$D+0\mathrm{.}75L+0\mathrm{.}75(0\mathrm{.}6W)+0\mathrm{.}75(LrorSorR)$

where $D=$ dead load, $L=$ live floor loads, $W=$ wind loads, $Lr=$ live roof

loads, $S=$ snow loads and $R=$ rain loads.

For the given roof member shown below $($ C is an internal hinge$),$ draw the

shear and moment diagrams given the following loads:

$D=70$ plf$,$ Lr$=120$ plf$,$ and $W=200$ plf$.$ Note that on member CB$,W$ is

acting in the opposite direction as in member AC$.$