An embodiment is an articulating straight-edge apparatus having an asymmetrical hub with a lobe having a flat edge. The hub has a bearing hole, an axle, a circular side with recesses which provide stopping at pre-set angles. There is a secant slotted channel through the lobe. The floor of the channel has depressions that provide stopping for translational shift. A connecting block is covered with a back and front plate. The block has an angle positioning SLD. The SLD impinges recesses as the hub is rotated. Additionally, there is a translational shift mechanism which includes a sliding rail in the channel. The rail has a SLD aligned to impinge a depression as the rail moves through the channel, therein stopping at a depression. Attached to the siding rail is a straight-edge element. The straight-edge serves as a carpenter's square, and can be adjusted angularly and translationally with manual force.