If I'm understanding what you are looking for correctly, then there are 2 solutions. I've re-attached your drawing with both solutions.
I feel like I should know how to do this without any construction geometry, but at this moment, this is all I'm coming up with.
One way to go about it, not requiring any Circle(s) as middle-men:
Fillet the horizontal and angles Lines at any non-zero radius.
Scale the resulting Arc, using the now-Apparent Intersection of those two Lines as the base point, with the Reference option: use the distance from that Apparent Intersection to the left end of the Arc as the Reference dimension, and take that to the Tangent/Quadrant point.
Trim or Extend [depending on how the Fillet radius you used compares to the "answer" radius] the two Lines to the scaled Arc.
....
OR [this does involve an intermediate Circle] if you don't want a Fillet-like result, but want the Lines left as they are, draw a Circle using the TTR option, tangent to the horizontal and angled Lines at any non-zero radius, and Scale it similarly [except that the Intersection won't be Apparent], substituting "top quadrant point of the Circle" for "left end of the Arc" in the description above, and trim the Circle to the two Lines.
hi afisher,
I actually did it the same way nestly2 has posted - just did up a drawing to show you what I did and then saw that they had already posted a nice video of it
bisect the large angle, extend to the vertical, draw the arc from that intersection.
GrantsPirate
Piping and Mech. Designer
Always save a copy of the drawing before trying anything suggested here.
----------------------------------------------------------------------------
If something I wrote can be interpreted two ways, and one of the ways makes you sad or angry, I meant the other one.
Can't find what you're looking for? Ask the community or share your knowledge.