Posted by LordOfBikes on Apr 10, 2020; 3:09pm
URL: https://forum.librecad.org/How-to-draw-2-circle-that-will-meet-in-their-radius-tp5718733p5718742.html

That's exactly how the above recommended tool Tangential, 2 Circles, Radius works.
Maybe you have missed the change in tool option bar when that tool is active. There you enter the desired radius, then select the circle and line.
Now you should see two white dots which represent the center of possible tangent circles.
Move the mouse near to the wanted circle to get a preview and click once again to finally place the tangent circle.

See also: https://librecad.readthedocs.io/en/latest/ref/tools.html#circle

Armin