OK, so r is 400mm and let's say that A is 30 degrees.
In that case, sin(30) is 0.5 so the opposite angle of the RAT with the blue line as the H is 200mm.
The A length is 346mm.
If you move the start point of the red line up by 200mm that means the A length of the RAT with red as the H is now 146mm. The angle B can be calculated as
OK, so r is 400mm and let's say that A is 30 degrees.
In that case, sin(30) is 0.5 so the opposite angle of the RAT with the blue line as the H is 200mm.
The A length is 346mm.
If you move the start point of the red line up by 200mm that means the A length of the RAT with red as the H is now 146mm. The angle B can be calculated as
tab(b)=200/146, so angle B is 53.9 degrees.