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I've been trying like mad to make an arc from two concentric circles connected by lines, by first joining the lines and the circles and then deleting the circles' arcs between them, as in the image:

Screen

But I can't seem to get it for the life of me, no matter what I do. I try to add extra nodes in the circle and then join selected nodes between the circle and the line, but it never comes through! Am I missing something?

  • Have you tried to use the bucket fill tool? It should create the shape. Or, alternately, you can use a box instead of the lines and proceed by difference. – Paolo Gibellini Nov 11 '15 at 9:40
  • The Paint Bucket would only add more copies of the circle/lines. I tried by difference using a rectangle and it wouldn't do anything. When I tried the union, the inner circle would disappear. I'm at my wit's end :( – Bruno Saramago Monteiro Nov 11 '15 at 14:21
  • I was meaning something similar to the solution of @AAGO: the first difference (between the circles) to obtain a ring shape, and the other difference (between ring and rectangle) to obtain the arc. – Paolo Gibellini Nov 11 '15 at 15:46
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This is not an exact answer to your question, but a quicker way to create the shape you described.

Draw the circles (grey), and a block (red) and align them as you like.

Then follow these 2 Steps:

Arc in Inkscape

  1. Select the circles: Path Operation Difference (ctrl+-)
  2. You now have a ring and a block. Select both and run Path Operation Difference again.
  • Just one more thing: does it work only in pairs of objects? Or is there a way I can select the difference between one object and many? – Bruno Saramago Monteiro Nov 11 '15 at 15:49
  • For DIFFERENCE yes, 2 paths. For UNION it doesn't matter. Have a look at the manual: tavmjong.free.fr/INKSCAPE/MANUAL/html/Paths-Combining.html – AAGD Nov 11 '15 at 15:52
  • I tried the method once and it worked perfectly. But on my second try (the following circles) it just made them disappear, regardless of the order I selected them. Is there any reason for that? – Bruno Saramago Monteiro Nov 11 '15 at 16:08
  • The order of selection doesn't matter. What does matter is the layer order (z-order). The path that cuts is the one on top (as mentioned in the manual link). So if this happens, select the cutting path and make it "Raise to top" (tavmjong.free.fr/INKSCAPE/MANUAL/html/Z-Order.html) – AAGD Nov 11 '15 at 16:30
  • Yes, it worked now! You're awesome man :) – Bruno Saramago Monteiro Nov 11 '15 at 16:39
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What you want to do is cut the circles with a path (the lines). The lines are temporary and are just used to get the nodes onto the circles in the correct spot. Next you need to combine the two circles (which will become paths after being cut) so that you can manipulate their nodes together.

Step by step

  1. Extend those two lines up and down to ensure that they fully intersect both circle paths (these are temporary lines, so they worry about it looking funny)

  2. Duplicate each of those lines once with Ctrl+D. There are now 4 lines (two on each side)

  3. Select one of the lines, then select a circle, then click Path > Cut Path.

  4. Repeat the above step with the other 3 lines. You will now have nodes on your circle exactly where those lines were and the lines will be gone.

  5. Select both circles, then click Path > Combine

  6. Using the Node Tool F2, delete the select of the path between the two nodes. You've be left with something that looks like this:

enter image description here

  1. Select the two nodes on the right, and then click the Join selected endnodes with a new segment button from the tool bar. Repeat on the other side.
  • First of all, thank you for your help. I tried what you describe but at the third step the circle keeps disappearing. The same thing that kept happening when I tried to join them. What do I do? – Bruno Saramago Monteiro Nov 10 '15 at 14:16

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