design questions A-frame chicken run

I am building an A-frame chicken run..........approx dimensions 10 feet wide and 6 feet tall and 16 feet long. Height is limited to 6 feet because of 2 foot overhang on coop roof. 12 year old grandson won't have any problem walking in this run for cleaning purposes.I will use the newly built floor of my 8x10 coop as a giant worktable while making roof trusses and also the A frame trusses for chicken run. The A frames for chicken run will be lagged into a 6x6 pressure treated timber base that is 16 feet long. I am wrestling with how to figure the angles. Any suggestions appreciated.

My basic approach:
- lay 2x4 rafters on coop floor..............use 3rd 2x4 to assure 10 foot outside dimension..........guesstimate the plum angle probably somewhere around 40 degrees and cut the plum line for rafter..........insert a 2x spacer (will be using a 2x ridgepole)..........and cut a complimentary angle (approximately50 degrees) so that end of rafter will lie flat on 6x6 base.

- determine exact lengths of rafters.........and cut 7 pairs of rafters..........am assuming I want to space them about 3 feet apart????

- clamp all the rafters for one side of A-frame together.......notch them all at the same time w a circular saw to accommodate (2) horizontal 2x4s..........one at the bottom where rafter meets 6x6 and 2nd cut approximately 3 feet from bottom of rafter---------repeat for other side..........cut plumb angle and complimentary angle on all rafters

-screw sample A-frame pattern to floor of my coop including 2x spacng for ridge pole

- lay a pair of rafters on top of pattern...........glue and nail a plywood gusset at apex.........turn it over and attach another gusset to other side

- have grandson#1 hold one A frame at one end of run while grandson #2 holds another A-frame at other end of run while gramps attaches a 16 foot ridge pole at both ends of run

-add additional A-frames at roughly 3 foot spacing........and then install (4) 16 foot horizontal 2x4s.........will be generous when notching 2x4s so that there is some wiggle room

- install a strip of 1/2 x 1/2 wire mesh 36" wide at lowest portion of both sides of run..........staple heavy duty galvanized 2x4 wire mesh over entire run to ward off any predatprs-

- we will have an additional 2 foot width of wire mesh under the 6x6 to thwart any burrowing predators

- build a heavy duty 2x4 access door for one end of run and we are done.......the other end attaches to coop

- debating whether I want to roof half of the run and add an outside roosting ladder so chickens have shade for daytime naps??? Thoughts on this?

Any suggestions or tips much appreciated.........will be making sawdust next week.........I found a very good A-frame guide on this web site last week but am unable to locate it now. This forum is a tremendous help

thanks and have a merry christmas