straightedge

And though the forms are simple, straightedge and mostly quadrilateral, they’re handled in ways that hint at 3D perspective.

Hunter is as straightedge as they come, but he’s, er, a difficult child.

In those days, proving a mathematical theorem was often as simple as drawing an elegant picture; the tools of ancient Greek mathematics weren’t pencil and paper—they were a straightedge and compasses.

A straightedge can be used to extend a line segment in any direction, and a compass can be used to draw a circle with any radius from the chosen center.

Check your wall surface using a straightedge to make sure it’s flat.