Hi OSTexo - that's an arc of a specific radius tangent to just one line?

You wouldn't use the Arc tangent command in MoI to create something tangent to just one line because that command in MoI is for creating arcs tangent to 2 or 3 curves simultaneously.

You can create an arc tangent to just one curve by using the regular arc from center point command and place the center point of the arc perpendicular from the line you want to be tangent with.

There are a couple of different ways that you can place the center point. If you know you want it for example 52 units displaced in the y direction you can use a relative point input to do that. To do that type in r0,52 before placing the center point of the arc and the center point will be displaced by that 0,52 vector from the point you snap on to.

Another way to do it is to activate distance constraint by typing in 52 and pushing enter, then drag out a construction line - there will be an End snap on the construction line at a distance of 52 units away from the place you dragged it off from.

You'll probably need to make the arc slightly longer than the target edge and then trim it off.

Let me know if none of these methods works for you or if I have misunderstood what you are trying to do.

- Michael