# Constraints disappear when selecting diagonal line

**URL:** <https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846>\
**Category:** Modeling Questions\
**Created:** [October 16, 2024, 12:26am UTC](https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846 "2024-10-16T00:26:31Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![baddog1016](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/baddog1016/32/27183_2.png) [@baddog1016](https://discourse.shapr3d.com/u/baddog1016)\
**Post date:** [October 16, 2024, 12:26am UTC](https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846/1 "2024-10-16T00:26:31Z")

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I am trying to make a circle tangent to a diagonal line. Typically I would pick the circle and then the line bit it doesn’t matter which order I do it. I select the two items and “Revolve around axis” command appears. Here is a link to a short video that demonstrates it

([https://youtu.be/whkBKdFSJ7o](https://youtu.be/whkBKdFSJ7o)). wrong link first time

I can draw another diagonal line and the tangent function works. I tried drawing a line and constraining it to be parallel to the line in question but when I selected both lines I also got the “Revolve around axis”.

[https://support.shapr3d.com/hc/en-us/requests/new](https://support.shapr3d.com/hc/en-us/requests/new)

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**Author:** ![baddog1016](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/baddog1016/32/27183_2.png) [@baddog1016](https://discourse.shapr3d.com/u/baddog1016)\
**Post date:** [October 16, 2024, 1:23am UTC](https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846/3 "2024-10-16T01:23:19Z")

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[[https://youtu.be/SfQ\_7NUfOw0](https://youtu.be/SfQ_7NUfOw0)]. this link should be the right one. I definitely have an issue with my constraints. Looks like it might be a Shapr3D issue.

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**Author:** ![TigerMike](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/tigermike/32/32650_2.png) [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)\
**Post date:** [October 16, 2024, 1:44am UTC](https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846/4 "2024-10-16T01:44:23Z")

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It looks like you have two different sketches either on the same plane or on slightly different planes which is why you’re getting the Revolve tool.

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**Author:** ![baddog1016](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/baddog1016/32/27183_2.png) [@baddog1016](https://discourse.shapr3d.com/u/baddog1016)\
**Post date:** [October 16, 2024, 2:57am UTC](https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846/5 "2024-10-16T02:57:00Z")

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I think the issue might be that I had the two vertical lines constrained vertically. I just redrew the lines and circles with no constraints in the vertical lines and it all worked as expected. However, if I look at the original drawing from left or right side all I see is a vertical line. When I sketch I pick the plane on the XZ face every time . In the drawing on the left the tangent constraint has worked between the vertical line and the circle. I undid it to make the video. I also added the lines and circle to the right to see if it would work there.

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<div class="post-metadata">

**Author:** ![baddog1016](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/baddog1016/32/27183_2.png) [@baddog1016](https://discourse.shapr3d.com/u/baddog1016)\
**Post date:** [October 17, 2024, 12:59am UTC](https://discourse.shapr3d.com/t/constraints-disappear-when-selecting-diagonal-line/34846/6 "2024-10-17T00:59:21Z")

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The answer seems to be that the items to be constrained need to be done in the same sketch