# SegmentGeometry - Where does it start to measure?

**URL:** <https://discourse.slicer.org/t/segmentgeometry-where-does-it-start-to-measure/37021>\
**Category:** Support\
**Created:** [June 25, 2024, 9:13pm UTC](https://discourse.slicer.org/t/segmentgeometry-where-does-it-start-to-measure/37021 "2024-06-25T21:13:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![CristianK](https://avatars.discourse-cdn.com/v4/letter/c/35a633/32.png) [@CristianK](https://discourse.slicer.org/u/CristianK)\
**Post date:** [June 25, 2024, 9:13pm UTC](https://discourse.slicer.org/t/segmentgeometry-where-does-it-start-to-measure/37021/1 "2024-06-25T21:13:23Z")

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Hi @jmhuie,

I am using SegmentGeometry to measure the second moment of area from ant mandibles. I am aligning them with the principal axis. However, I do not understand where the start (1%) and end (100%) of the measurement are. How can I figure this out?

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**Author:** ![jmhuie](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jmhuie/32/7086_2.png) [@jmhuie](https://discourse.slicer.org/u/jmhuie)\
**Post date:** [June 25, 2024, 9:50pm UTC](https://discourse.slicer.org/t/segmentgeometry-where-does-it-start-to-measure/37021/2 "2024-06-25T21:50:12Z")

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Hi Cristian

The easiest way to tell is to look at the slider and values at the top bar of the slice view. 1% will be more to the left and smaller values. 100% will be more to the right and larger values. See the attached photo to get a better idea of the slider and values I’m referring to.

Best,  
Jonathan

 ![Screenshot 2024-06-25 at 5.45.00 PM](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/b/0b0a623c7189cebcbd363d398829bf63b76dafac.png)