There is a better way with ProLine:
ProLine © Dezmo 2018-2019
Draw edges or Line entities like in a native Line Tool but
Draw edges / curves / clines / cpoints entities with special protractor and inference assistance!
Motto: I hope you will enjoy using it half as much as I enjoyed creating it!
I would like to draw your attention that I made a new Extension / Plugin. I did it for myself, to learn and practice, but You may find it useful too… You can download and use it free of charge on your own risk.
Currently the Release Candidate version available only in Pluginstore: Dezmo ProLine!
You can find more detailed post about it on Sketchucation forum:
Sketchucation:[Plugin] ProLine
I also prepared documentation for the ProLine Extension, it is included inside the downloaded file (Dezmo_ProLine_vRC-2019_0105_1209.rbz), please read it.
The idea:
In the recent versions of SU we do have a “Rotated Rectangle” tool, so called protractor assisted rectangle creation. In the other hand reading the forums some people are asking to snap the line not only to length, but to angle as well…
Why should’nt we have a “Line” tool with protractor assistance?
This is a reason I’m created a tool: Protractor Line. The name is shortened as “ProLine”, so it is also representing some more, hopefully useful, functions to create a line in SketchUp in advanced way.
I’m not a programmer or 3D designer, I just like to discover Ruby & SketchUp.
Note:
The tool is in Release Candidate stage. However I did my best to give it out without serious errors, an unexpected problems may occur… download and use it on your own risk.
Tested: SketchUp pro 2014 on windows 7, SketchUp pro 2015&2018, SketchUp make 2017 on windows 10.
It was created and only tested in a windows environment and may not (properly) function on a MAC.
Please keep in mind that my Mother did not speak to me in English. 
Enjoy! 
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