Hi Sven, Barry has the right solution above (thank you Barry). Just in case it's not clear it's done by creating this construction geometry -

A 57mm circle centered on the juncture point:



Offset these lines also by 57mm:



The intersection between the circle and the offset lines will yield the center of the arcs:



So then draw an arc from center point, put the center point onto that circle/offset line intersection, first point of arc at the juncture point and the last point at the snap point on the original lines.

- Michael