LGS 2D 4.0 Version 4.0 of LGS 2D completely supports orientation and alignment attributes for all kinds of geometric and dimensional constraints. An alignment attribute can be applied to any constraint involving two non-point entities: tangency, distance, parallelism, or perpendicularity between lines, circles, curves or ellipses. It specifies whether the tangent vectors of the constraint arguments are co-directed or counter-directed. Orientation attribute is applied to distance constraints (except point-point distance) and controls whether one argument will be positioned to the left or to the right side of the other one. Orientation and alignment attributes provides users of the applications built on top of LGS 2D with the full control of a constraint chirality. Current example demonstrates using the alignment of line-circle tangency constraint to properly position a connection arc, as well as using undefined orientation of point-line constraint to switch the side of the point’s position with respect to line (in previous LGS versions only oriented point-line distance constraint was supported).