I'm working on making some gauges to determine the radius of a curved surface. I'll use a laser to cut a few different radii templates and see what fits the curve.

I had an old inkscape version installed on my 64 bit windows 7 laptop until yesterday. I removed it and installed the current version, 1.3.2. I'm not an experienced inkscape user but I've managed to get my page size right and output the thin red vector line to the laser.

I can draw an arc but it is awkward to manipulate things so I have an arc from a three foot radius circle across the top of my 27 inch wide page. I'd like to be able to draw the arcs by entering numeric parameters, e.g., r=36, x(center)=27/2, y(center)=r+1, (0,0 in top left for this example).

I've searched for how to to this but everybody seems to draw their arcs with a mouse. Thank you for your help!

It might be worth looking at this extension.

Look at the arc section halfway down the page.

https://github.com/spakin/SimpInkScr/wiki/Shape-construction

The Ellipse tool has numeric entry in the controls above the top ruler.

Thank you both. That script looks promising. I tend to prefer text input like PostScript and HPGL. It would be cool if there was a command line interface that understood those languages (and gcode).

I've now found the numeric input fields. Now I can draw my arc segment.  How can I center it where I want?

Vector shapes by their nature have a numerical definition. Inkscape is primarily a graphic design application so it doesn't do CAD very well, but you can access the underlying structure of your drawing.

Select the arc and open the XML Editor [Edit > XML Editor...] or [shift+ctrl+x]. In the right panel you will see the parameters defining an elliptical arc, which can be edited. You can move the centre to new coordinates by selecting and changing the values of [sodipodi:cx  99.99] and [sodipodi:cy  88.88].

Now I know enough to finish my project. I recently lost my access to autocad and illustrator when I retired from my school job. I have lots to learn about inkscape but it looks like it will handle most of my needs. Thanks again, everybody.