Rotate to exact point

[PHBK]

Hi, I hope theres a easy solution.

Problem:
2 poles, with a angled support. Support is exactly 15 cm from ground, going to very top of next pole (see 1st picture)

What I did so far:
I anchored the support to the 15cm point at the lowest corner of support.
Then trial and error with angles, until it was as close to top, as possible.
Leaving 0.15 cm (as close as it gets)
Is there any trick or other way, than using rotate 0.13742 to make exact fit to corner?
Would love, if it was possible to anchor to point, then rotate to another point.

I'm not sure its possible, but do hope I have overlooked something 

Thank you in advance.

[AlwMVMO]

It took me a little while but I knew I had done something like this before.

It involves drawing a circle at your pivot point with a radius of your support width and 
then drawing a line tangent to the circle and the intersection of the 15 cm.

Then parallel line the other side of support which goes thru the center of the circle. 

   

[PHBK]

(06-23-2022, 11:44 PM)AlwMVMO Wrote: It took me a little while but I knew I had done something like this before.

It involves drawing a circle at your pivot point with a radius of your support width and 
then drawing a line tangent to the circle and the intersection of the 15 cm.

Then parallel line the other side of support which goes thru the center of the circle. 

Of course, its brilliant and genious. And exactly spot on, that way.
I thank you so much for this solution
I never thought of that.
Thank you

Edit:
Just tried your solution (knowing it would work)
And it works beautifully 
Thanks to your great description how to, i was never in doubt.

And making a fence door (Spelling correct?) was a breeze this way.
Been struggling so hard and so long, now I will not forget