Problem $3$: Determine the force in members $FD$ and $DB$ of the frame, and the support reactions at A and $C.$ Also, find the horizontal and vertical components of the reaction force that point $C$ exerts on members ABC and EDC $($Hint: the external horizontal force at $C$ is zero because it is a roller, but do not let that fool you$-$the pin support at $C$ can still exert a non$-$zero internal horizontal force on members ABC and EDC $).$