This method produces a different measurement than the trig one… I will test the pattern on a muslin and with a future different hip measurement to assess further. But you’re right, I don’t think minor difference in measurements by few cm/an inch would distort a garment that much. Small fit adjustments are usually needed afterwards anyway.
Thanks for your input!
As I feared. I was totally missing the obvious solution! Many thanks!
Not that I can’t do trig… I just try to avoid it when possible. 
i do know though the 30 / 60 and 45 right triangles inside and out.
I think it stems from experiencing my batteries going dead in my calculator during an Applied Physics exam in college, where I had to resort to the old fashion way of looking up in the trig tables and manually doing the calculations. Lol