Editing Objects with AutoCAD - Section 4

17.6 Extend

The Lengthen command, which shares a button with the previous command, Trim, extends one or more objects to the edge of another. This command can not be executed with circles, ellipses, rectangles or other closed polylines. But it can be executed with lines, arcs, elliptical arcs, open polylines and splines. Like the previous command, the Border and Capture options, which appear once the objects that will serve as borders, are used to select the objects to be extended. Also, once again, the Projection and Edge options apply to the 3D environment, so they will be viewed at the time.

17.7 Rotate

On many occasions the name of the command clearly indicates what it is and there are no specific procedures to detail, so developing explanations about it becomes tautological, if not a truism. Personally I am amused to think that I would have to write, as in many computer books actually done, things like the following: The Rotate command is used to rotate objects. Although I do not doubt that in many cases, among all the titles of the Immediate Guides of Computing, I must have incurred such atrocities and even more than once in this same text, but sometimes you have no choice but to do so.
But, it is the case that rotating objects requires a reference point, a center from which the angles of rotation are counted and that point must not necessarily be part of the object, it may be outside it. In turn, the angle of rotation can be indicated in the command window or we can use the mouse to freely rotate the object. Finally, it includes the Copy option, so that the original is kept unchanged (all of which indicates that there were always procedures to detail).

17.8 Length

The Length command, like Extend, can not be applied to closed objects. When you execute it and select an object, it shows the length of the line segments or the included angle of the arcs. Your options are listed below:

a) Increase. Modify the length of the object by adding the indicated value. In the case of arcs increases the value of the angle.
b) Percentage. Take the current length of the object as 100%, if we write 120, it increases the length by an 20%. If lower values ​​are set to 100, the length is reduced.
c) Total. Allows the capture of a value that will be the absolute length of the object to be edited
d) Dynamics. Activates the option to drag the closest endpoint of the object, changing its length.

Obviously, if we do not have other reference objects to lengthen an object, the Length command is the alternative, since we can modify the objects by reference to their own current length.

17.9 Align

This editing option allows you to align one object to another and even modify its scale. In the 2D drawing, 2 points are enough to make the alignment. Let's look at the following example: