Which tools do you use to measure bike hip angle?

Is there a practical way to measure bike hip angle at home? Not asking from where to where to draw the lines, but actually how to do it and take the angle without needing to go to a bike fit studio to do so.

I use this:

https://www.mcmaster.com/#8521a34/=1e1eaqj

Digital Protractor
18" Long Arm
.

I use Bike Fast Fit, which seems to be about as accurate as your ability to identify your anatomy.

I’ve used this too:

http://trophy-box.com/bikefit/perspective.html
.