How to draw a circle tangental to two arcs and a straight line

[caigner]

How to draw a circle tangental to two arcs and a straight line?

Here is what I got:

Circle_from_3_Tangents.png (5.38 KiB) Viewed 2864 times

I want to draw a circle which is tangental to all three segments, the two arcs and the straight line.

It is not difficult to fit a circle between the two arcs, but how to make it touch the straight line in just one point?

It should look like this, only without that gap where the circle touches the line.

what_I_want.png (8.67 KiB) Viewed 2864 times

How can I do that?

[andrew]

I'm assuming the arcs are concentric, so you know the radius of the circle already.
A parallel to the line with distance=radius will give you the circle center (as intersection point).

[caigner]

Thanks!