# Vector.AngleAboutAxis returns wrong value for 45 and 225 degree values

**URL:** <https://forum.dynamobim.com/t/vector-angleaboutaxis-returns-wrong-value-for-45-and-225-degree-values/107941>\
**Category:** Uncategorized\
**Tags:** revit, dynamo, vector\
**Created:** [February 12, 2025, 12:32pm UTC](https://forum.dynamobim.com/t/vector-angleaboutaxis-returns-wrong-value-for-45-and-225-degree-values/107941 "2025-02-12T12:32:44Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![sstefanovicXYV7V](https://avatars.discourse-cdn.com/v4/letter/s/ccd318/32.png) [@sstefanovicXYV7V](https://forum.dynamobim.com/u/sstefanovicXYV7V)\
**Post date:** [February 12, 2025, 12:32pm UTC](https://forum.dynamobim.com/t/vector-angleaboutaxis-returns-wrong-value-for-45-and-225-degree-values/107941/1 "2025-02-12T12:32:44Z")

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So I’m building this script to place duct hangers at specific distances and the final step is to use the duct lines as driver of the direction of the hangers themselves.  
Using this node Vector.AngleAboutAxis I’m getting the wrong angle values as you can see.  
Would appreciate immensely any suggestion.  
packages used:

- bimorphNodes
- Clockwork for Dynamo 2.x
- MEPover  
 ![Screenshot 2025-02-12 133058](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/1/0/105a11df1bc015d39a3e8b05e916eae08da2a867.png)

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**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\
**Post date:** [February 12, 2025, 1:54pm UTC](https://forum.dynamobim.com/t/vector-angleaboutaxis-returns-wrong-value-for-45-and-225-degree-values/107941/2 "2025-02-12T13:54:00Z")

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Can’t really see what is off on this as we don’t have a source model or a way to see one ducts which is wrong. You can build such a sample with Dynamo using a line creation node (ByBestFitThoughPoints works easily enough, or ByStartPointEndPoint), and then a Line.Direction node to get the direction you drew it, and finally get the angle as before.

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**Author:** ![sstefanovicXYV7V](https://avatars.discourse-cdn.com/v4/letter/s/ccd318/32.png) [@sstefanovicXYV7V](https://forum.dynamobim.com/u/sstefanovicXYV7V)\
**Post date:** [February 13, 2025, 8:31am UTC](https://forum.dynamobim.com/t/vector-angleaboutaxis-returns-wrong-value-for-45-and-225-degree-values/107941/3 "2025-02-13T08:31:46Z")

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![ELK_Round Duct support placement](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/4/a/4a40b21b586787c77eddeb2c3c0ba3e232852f69.png)

I also tried that at one point 😃

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**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\
**Post date:** [February 13, 2025, 8:44am UTC](https://forum.dynamobim.com/t/vector-angleaboutaxis-returns-wrong-value-for-45-and-225-degree-values/107941/4 "2025-02-13T08:44:07Z")

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I still can’t tell where the angle is being calculated incorrectly here. We need a simple producible case such as four lines drawn in Dynamo giving you two or three angles which you think are incorrect.