The orthogonal command finds orthogonal objects. It takes its arguments in different ways, and returns and draws a line or plane, depending on the arguments.
orthogonal(point(0,0,0),line(point(1,0,0),point(0,1,0))) |
perpendicular(line(point(0,0,0),point(1,1,0)), plane(point(1,0,0),point(0,1,0),point(0,0,1))) |