Alright. Important stuff if you want to build one of these.
All the measurements in that layout work, and they all need to be adhered to. The 17.5 inches at the top is perfect for the panel to sit on so one longitudinal wire and two latitudinal wires sit on top of it for support.
The 39 inch width at the top of the door and window is also mandatory...the outside of which is where your 10 foot 2x4 that connect the front and back walls will sit, so the distance from the top of that angled board to the corner of the door frame needs to be slightly more that 3.5 inches...and you should miter those ends, which I didn't do.
When you go to buy the panels, ask if they have any damaged ones. I haul these from the manufacturer, and the straps damage the top panels of every bundle. It's just a couple of 4" bends (the width of a strap) on one edge.
It takes three to make make one of these, so I bought two damaged and one new. Since the center panel overlaps 4 inches over each of the others, put a damaged one front and rear with the damage in the middle and overlap the good panel there. Saved me $10...$65 total for three panels.
Counting from the corner of that 17.5 inch vent board on top, there are 11 opening in the panel on each side and 2 over the top.
You'll need to do some measuring to figure your overhang on the front and back so you end up with 4" overlap on for your center panel. Then you're going to need some vice grips and bailing wire to make everything line up and increase the rigidity of your panel connections.
I'll post the measurements of that tarp tomorrow.