Framing Gabled Dormer for idiots... and is it called a gabled dormer?

I'm building a greenhouse and want what I think is called a gabled dormer, or wall dormer. I can't seem to find a clear answer on what this is called. Either way, the issue is how to figure out the cuts for the main roof valley rafters and dormer valley jack rafters.

I found on-line calculators for the common rafters that give me the rafter length based on rise/run and also did the roof pitch calculator (8:12 with 43.27" rafter length). I then found a calculator for locating and cutting birds' mouth. That is a little trickier (for me) and will practice all this with scrap wood.

My problem is I can't find an "Idiots Guide" to figuring out the angles to cut on what I think is called a gabled dormer. Does anyone have a link to a video that clearly explains this? I've found a few, but not that instructive for someone who's never done it. It appears the valley rafter would be 45 degrees off the dormer ridge beam, and the valley jacks would be 45 degrees off that?

The shed roof below is an example of what I want to do. The diagram I found online below that shows the framing, however it doesn't go to the ridge beam like the shed does.

 

Check YouTube for how to use a speed square for valley framing.

Framing calculators are handy.
https://youtu.be/NAZ0kFeU-xY