Menu: Geometry->Edit->Line operations
With this option you can edit groups of lines with respect to their topology and shape.
Join lines end points:
With the command Join lines end points, two lines must be selected. GiD determines the distance between the two closest endpoints, draws both points, and asks for confirmation. If one of the lines is a polyline, interior points are also considered. If accepted, the points are converted into one and the lines are distorted. The new point will then take the place of the first line's point.
(See Move point for another method of converting two points to one.)
Caution: The second selected line cannot have higher entities (the second point is moved to the first).
Force to be tangent:
With the command Force to be tangent, two lines (which share at least one point) must be selected. They must be NURBS lines, otherwise they will be rejected. You are asked to enter the maximum angle between lines to accept the operation, and GiD will modify the selected NURBS lines and force them to be tangents at their common point.