# Dimensioned curved line

I am looking to take a 10’ line and then curve it at the center point so the two ends end up 3’ apart with an arch at the top. These doesn’t seem to be satisfied by the ‘spline’ tool which doesn’t have dimensions? Am I using it wrong or is their a work around? I either need to be able to change dimensions between spline points or add spline points to a ‘line’ object. TIA!

Edit: I see I can get the linear distance between two spline points, but I need to be able to modify the true line distance.

Is this what you are trying to achieve?
If so, I sketched the 3 lines per your requirement and then Locked them. Now you can sketch an arc and make tangent to the 10’ length line.

There’s another approach if you’d rather sketch a spline curve instead.

@TigerMike , neat video firstly. I’m going to learn how to do those. That’s not quite what I’m trying to do. In your demo, I’m trying to do the length of the arc itself as 10’. And then it would need to be ‘squished’ so the to ends were 3’ apart from one another; so it would end up looking more like half of an ellipse. To think about it more concretely, I’m am starting with a piece of 10’ rebar, and will be bending the two ends together to create an arch. Does that make sense?

A better way to describe (if I get my terminology right) would be: “Draw an ellipse with with a perimeter length of 20’ and a minor axis length of 1’ - 6” ”

I think I was able to solve this by using an online calculator to calculate the perimeter of the ellipse to 20’ given a minor axis of 1’-6”. This gave me a major axis of 4’-6” which I was able to plot into my sketch of an ellipse. So half my resultant perimeter will be 10’. Let me know if I made some math assumption in error there!

I get it now. Obviously I misunderstood. Out of curiosity, how exact does the 10’ length of rebar have to be after bending (which by they way there is no way to bend lines in Shapr3D)?

You can do it via a few simple iterations of sketching an ellipse 18" x some number zeroing in on 53.9". This yields an arc length of 120.1". And you are ending up with a half ellipse and not messing around with a spline. Your thoughts?

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That works! Thanks for the help.