# Can we measure angles on the 3Dslicer

**URL:** <https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501>\
**Category:** Support\
**Created:** [November 21, 2017, 8:50pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501 "2017-11-21T20:50:24Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![patsawas](https://avatars.discourse-cdn.com/v4/letter/p/df788c/32.png) [@patsawas](https://discourse.slicer.org/u/patsawas)\
**Post date:** [November 21, 2017, 8:50pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/1 "2017-11-21T20:50:24Z")

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Operating system:  
Slicer version:  
Expected behavior:  
Actual behavior:

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [November 21, 2017, 9:59pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/2 "2017-11-21T21:59:10Z")

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There used to be an angle measurement widget in Slicer but then it had to be removed temporarily until the underlying infrastructure is cleaned up.

Until this widget becomes available again, you can use this module for measuring angles:

> <https://gist.github.com/lassoan/9bf334743871e400f7e3b3745b312b14>

You have to place two rulers and the module shows angle between them. You can click on “Add to table” to add the measurement to a table and remove the rulers.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/b/7b82643b300a106394847bea8808e847dae02365.png)

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**Author:** ![stevenagl12](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/stevenagl12/32/3391_2.png) [@stevenagl12](https://discourse.slicer.org/u/stevenagl12)\
**Post date:** [March 19, 2018, 7:57pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/3 "2018-03-19T19:57:01Z")

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Has this ever gotten updated so that the widget is available?

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**Author:** ![stevenagl12](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/stevenagl12/32/3391_2.png) [@stevenagl12](https://discourse.slicer.org/u/stevenagl12)\
**Post date:** [March 19, 2018, 8:15pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/4 "2018-03-19T20:15:02Z")

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Also, for whatever reason, any time I record an angle with this script. The rulers are cleared instantaneously, is there a way to preserve the rulers?

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**Author:** ![stevenagl12](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/stevenagl12/32/3391_2.png) [@stevenagl12](https://discourse.slicer.org/u/stevenagl12)\
**Post date:** [March 19, 2018, 8:32pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/5 "2018-03-19T20:32:40Z")

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Not sure if the given script is working correctly either because I ran it on

![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/9/892542e5d18472d97e62195bc15e44006134b7d4.jpeg)

and it gave me an angle of 137.4.

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [March 20, 2018, 8:00pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/6 "2018-03-20T20:00:24Z")

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> [@stevenagl12](#):
>
> it gave me an angle of 137.4.

Yes, that looks correct (about 45 deg less than 180 deg). Note that the order of points matter, not which endpoints you place close to each other.

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [March 20, 2018, 8:01pm UTC](https://discourse.slicer.org/t/can-we-measure-angles-on-the-3dslicer/1501/7 "2018-03-20T20:01:51Z")

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> [@stevenagl12](#):
>
> The rulers are cleared instantaneously

This is a feature. This allow you to make many measurements. You can change the script to not clear previous angles.

I’m working on improving widgets. I’ll first add curve widget, but soon after I’ll add proper angle measurement widget. It should be available in a few months.