How to measure the angle?

This link should work better:

When i click the link,the result i got is “the webpage in not exist”!
The module about angle measurement has not been finished,is it right?
Thanks a lot!

The webpage ( does exist and loads fine for me. Check your network settings and try again.

The preview in the post shows the first 10 lines, but the module is complete (see at the link), you can use it as is.

Hello,professor Andras Lasso!
After I have tried some times,the webpage still can not been openned eventually.I checked my computer and the web setting,but there was no problem.
So I want to know is there any other methods or modules can measure the angle between two lines?
Thanks a lot!

The GitHub link above ( still works, I’ve just checked this again.

Which country you are in? Do you have access to github and gists on github in general?

hello,professor Lassoan!
I am in China,probably the webpage was forbidden by “some authorities”.I do not know the reason.What I want to do is to measure the angle between two lines or three lines,the question troubled me for a long time!can you teach me some other ways or methods?

Thank you very much!

Do you have access to github repositories? For example, do you see files in this repository?

Do you have access to github gists? For example, you can try to create a gist and see if you can access that.

Thanks a lot,Professor Lassoan!
I have registered an account on the GitHub web and I can open the repository you gave me.
Because I am a new user of 3D Slicer,I donnot know what I should do next?
Would you like show me the details about how to measure the angle between lines?
Thank you very much!

Add the directory where the .py file is located to the “Additional module paths” in Application settings / Modules section. If you restart Slicer then the “Angle measurement” module will show up in “Quantification” category in the module list.

Thanks a lot!
But how can i get the *.py file?
Is in my computer already? or I should download it from the link you give me?
Thank you very much for your attention, Professor Lassoan!

You download the file and save as

I have tried some methods some times,but the webpage( cannot be openned and I cannot find **the file** in the end.So the problem have not be solved.Is there any way can I get the file?
Thank you very much,Proffesor Lassoan!

Hello,Professor Lassoan!
After open the home page,what should I do or which file should I search in the page?
Thanks a lot!
home page

What file sharing service is allowed in China?

Thanks,Professor Lassoan!
Do you mind send the file(*.py) to my mail account?
My mail address is
Thanks a lot!


I wanted to calculate the angle between two ruler lines in Slicer. I found the file.
But where should I put this file and I wanted to know the steps how to add that file in Slicer and how to measure the angle?


Similar question was answered here: How to measure the angle?

Otherwise, to provide some background, similarly to the ruler, there is preliminary work to support angle and it would still need some work. Code can be found in the Annotations module.


Thank you very much for the angle measurer. @lassoan, is there a way to define the module for several rulers with a chosing panel to select the rulers ? I have multiple rulers for a project and I would require to be able to choose the rulers when needed instead of deleting every rulers after measuring the angle.

Thanks in advance,

Angle widget is available in recent Slicer Preview Releases. Let us know if they fulfill your needs.

Thank you very much sir !

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