Beam Annotation

Hi,

I want to create annotations for each beam in the view. I found several different posts related to annotation but to be honest I got lost.
I want two types of annotations as you can see in the screenshot. First overall width of beam from face to face, second is face to center.
beam

I started to write something but it is too far from finishing the script yet.
It helps even if you can give me a starting idea so I can get some results at least.
Thank you very much.