# Connecting 2 circles with a tangent line

**URL:** <https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537>\
**Category:** Modeling Questions\
**Created:** [February 14, 2025, 9:19pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537 "2025-02-14T21:19:33Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Satims](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@Satims](https://discourse.shapr3d.com/u/Satims)\
**Post date:** [February 14, 2025, 9:19pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/1 "2025-02-14T21:19:33Z")

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I want to connect two circles with a line, that intersect both circles as a tangent. Is there a way to do this easily?

When selecting a point and a circle, it shows you where the tangent points are, but you can do this with 2 circles, because they have no points.

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**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 14, 2025, 10:08pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/2 "2025-02-14T22:08:52Z")

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Do you have auto constraints ON or OFF?  
I often prefer to set constraints myself.  
Draw first circle (you may want to set the diameter and lock the origin of it)  
Draw second circle (do same)  
Now draw a line between the two circle lines (snapping to the lines)  
Click on a circle, then shift click on the line, then set Tangent constraint.  
The line will adjust to the tangent position.  
Repeat for other circle.

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**Author:** ![Satims](https://avatars.discourse-cdn.com/v4/letter/s/57b2e6/32.png) [@Satims](https://discourse.shapr3d.com/u/Satims)\
**Post date:** [February 14, 2025, 10:17pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/3 "2025-02-14T22:17:04Z")

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You’re a life saver, thank you. Not sure what I was doing wrong, but for hours mine was either moving one of the circles or changing their sizes.

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**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 14, 2025, 10:26pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/4 "2025-02-14T22:26:06Z")

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If you find that happening, always remember you can lock a point of the geometry.  
Useful on circle centres.  
But remember that if you want to move elements of a sketch you will have to unlock those points.  
By default you select the item you dont want to move first then the second item you choose is the one that adjusts.  
Constraints are really useful, and you can acheive lots with them.

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**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 14, 2025, 10:34pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/5 "2025-02-14T22:34:45Z")

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With practice you can use your sketch constraints to allow dimension adjustments on the fly.  
This video is of a spiral for a clock type spring.

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**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 14, 2025, 10:38pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/6 "2025-02-14T22:38:26Z")

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Also one thing I wanted to add, the order of the constraints is important if you didn’t lock.

Select Circle first and Line last to add tangent constraint.

You can do some funky stuff.

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**Author:** ![arroniow](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/arroniow/32/30268_2.png) [@arroniow](https://discourse.shapr3d.com/u/arroniow)\
**Post date:** [February 14, 2025, 10:48pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/7 "2025-02-14T22:48:03Z")

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😉  
I did also mention in the second post that by default you select the item you dont want to move first.  
You can of course change which is the Anchored Sketch entity in constraint settings.  
That is another useful video for constraints and the flexibility they bring.

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**Author:** ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)\
**Post date:** [February 14, 2025, 10:55pm UTC](https://discourse.shapr3d.com/t/connecting-2-circles-with-a-tangent-line/36537/8 "2025-02-14T22:55:04Z")

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Actually that part was what I wanted to clarify, thinking in order of step 1 and step 2, but logic is the same, because order doesn’t matter if you have locked it already.