I am currently using QCad community edition, and it is basically well suited to my needs, I don't need much more. However, there is a function I need which isn't present in QCad. I want to be able to specify a point on a line (which can be a straight line, arc, ellipse arc or spline) and say "go to the left/right and cut the line after X millimeters".

For most of these, I have a workaround using Divide and Lengthen (after an annoying step involving getting the total length of the line and a calculator). But it turns out that QCad cannot measure the length of an ellipse arc. I know that the formula for an ellipse arc is much more complicated than that for more conventional geometric shapes, but for a computer program running on hardware with a bazillion FLOPs, I don't see how this is a problem.

So is there a CAD software which is at least capable of measuring the length of an ellipse arc? It would be perfect if it would have said trim capability built-in, but I'll still take it if it needs a workaround.

I cannot afford commercial CAD software. I prefer open source, but if not possible, I'm OK with some crippled demo version which cannot import DXG or such, as long as I can create some drawings. I don't need any of the features which industry people use to turn drawings into real products. If there is a commercial edition for home users with a price to match (up to 50 Euros), I'll consider it too.