Snap Circle Circumference to 2 Lines

How do you snap a circle circumference to the end nodes of 2 skewed lines?

In the diagram, the circle will snap to line A; after moving the circle rotation point to the end node of line A at the point of contact, I then click and pivot the circle hoping to make contact and snap to the end of the second line B.  It comes close, but never actually snaps.  In wireframe and zoomed greatly, you can always see that the circle never really snaps to the second line. Thanks!