Constraint line angle when resizing?

[bartoszkowalski]

Hey. I've been using CS6 until it recently became unsupported on macOS. Using Illustrator 2020, is there a way to constrain the angle of a line/path when resizing it? For example, Affinity Designer does it with with a hold of the shift key. I know there's a "constrain angle" setting in the prefs, but that's a global change. I'm wanting to grab any line on my dartboard and change the length without changing the angle.

Thanks for any help!

[tromboniator · Accepted solution]

Turn on Smart Guides (View menu > Smart Guides). With the Direct Selection Tool click to select the endpoint of the path you want to extend and drag in the direction you want it to go. Smart Guides will indicate "on" at the moving point when it's on the correct path, and "Line Extension" at the point on the other end. This only works for a straight path coming out of a corner point; otherwise, if you have them active, you will see construction guides at the angles prescribed in the preferences.

Peter