As we have just mentioned, the geometric constraints establish the arrangement and geometric relation of the objects with respect to others. Let's look at each one:
This restriction forces the second selected object to match some of its points with some point on the first object. As we move the object selector, Autocad is highlighting the different relevant points of the geometry that we can match the point of the other object.
It relocates to the second line selected to be collinear with respect to the first line.
Forces circles, arcs, and ellipses to share the center of the first selected object.
Sets the location of a point as fixed, the rest of the geometry of an object can be modified or moved.
Modifies the arrangement of the second object to be located parallel to the first selected object. It is also defined in the sense that the line must maintain the same angle as the reference object. If a segment of a polyline is selected, it will be the one that changes, not the other segments of the polyline.
It forces the second object to be perpendicular to the first object. That is, to form with it an angle of 90 degrees, although both objects do not necessarily have to be touched. If the second object is a polyline, only the selected segment changes.
Horizontal and Vertical 12.1.7
These constraints fix a line in any of its orthogonal positions. However, they also have an option called "Two points", with which we can define that these points are to each other which must remain orthogonal (horizontal or vertical, according to the selected constraint) even though they do not belong to the same object.
Forces two objects to touch tangentially. Obviously, one of the two objects must be a curve.
Forces a spline to maintain the continuity of its curve with another object.
It forces one object to remain symmetrical to another with respect to a third object that serves as an axis.
Match the length of a line or a segment of a polyline to another line or segment. If applied to curved objects, such as circles and arcs, what equals then are the spokes.