Lining up Sprinkler Heads the Easy Way, by Making Perp the Perpetrator

One often overlooked feature of the PERPendicular object snap is the ability to line up an object (such as a head) with other objects (other heads). To wit - the two heads below in the Dispatch Office are not lined up with the head plan north of it already piped. How to line up these two heads? Use PERP

Pick the two heads and activate the MOVE command. Then choose the insert or center of the heads as the base point. Then click the PERP osnap and select the pipe already drawn, and the heads will be move to line up with them: