# Compute intersection of lines

**URL:** <https://discourse.slicer.org/t/compute-intersection-of-lines/19989>\
**Category:** Support\
**Created:** [October 4, 2021, 1:45pm UTC](https://discourse.slicer.org/t/compute-intersection-of-lines/19989 "2021-10-04T13:45:34Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jumbojing](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jumbojing/32/10811_2.png) [@jumbojing](https://discourse.slicer.org/u/jumbojing)\
**Post date:** [October 4, 2021, 1:45pm UTC](https://discourse.slicer.org/t/compute-intersection-of-lines/19989/1 "2021-10-04T13:45:34Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/0/1080c3654851afc3528974955677e99f688c0048.png)

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**Author:** ![mikebind](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@mikebind](https://discourse.slicer.org/u/mikebind)\
**Post date:** [October 4, 2021, 4:18pm UTC](https://discourse.slicer.org/t/compute-intersection-of-lines/19989/2 "2021-10-04T16:18:47Z")

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This probably isn’t the right forum to be asking this question. It looks like a similar triangles question, but I don’t see the solution right off. It is not too hard to show that the two triangles below MI are similar to triangles AIM and ALM, but I don’t immediately see how to find the scale factors which would allow solving for all the lengths.