# Thread: find the center of a broken ellipse

1. ## find the center of a broken ellipse

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I'm trying to trace a plan where an ellipse was used for the general shape of a room. Since doors were added, the ellipse was broken into splines. Now I want to retrace the original ellipse but don't know where to start or how.

BTW, the ellipse was drawn at an unknown angle.

2. put some lines where you expect the quadrants of the ellipse. then extent the pieces. now you get actual the quadrant points of the ellipse. snap the quadrants using osnap - qua. now you have the major and minor axis by joining the quadrants. centre of the ellipse can be snapped even in the broken condition. or give extend command. right click once more. then pick the ends of the pieces. it will extend to form the full ellipse.

3. put some lines where you expect the quadrants of the ellipse.
Thanks for the reply.

This is what I am trying to avoid, guessing. Of course I can assume the quadrant points but I am looking for a way where I can really hit the right spot.

4. Try this

1. Set your osnaps to centre and perpendicular
2. Draw a line from the centre of the ellipse (it should still snap to it)
3. Draw to the original quadrant of the ellipse (it should snap to perp)
4. Scale the line by 2 - you now have one of the axes
5. Repeat the above for the other axes.
6. Draw the ellipse using "Ellipse axis end"

5. give extend command. right click the mouse once more (extra). then pick the ends of the ellipse. it will extend eventhough it is brocken to form a full ellipse. now by snapping to the quadrant points you can make the axes.

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Thanks for the replies.

Sorry I didn't mention that the quads are no longer there. All that's left were splines. Anyways, I think I kinda figured it out but my process is somewhat i-guesses.

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