Was a little hard to get photos of mine. I have about 32 sq ft of ventilation NOT including doors in a 6x10 coop. All have hardware cloth sandwiched or secured with screws/fender washers.
These vent holes are just under the roof line at the top of the coop wall, there's 40 total:
View attachment 1788268
Ridge vent in the roof and the inside view of a gable vent:
View attachment 1788269
I have 5 windows that stay open almost all year, plus you can see the gable vent and one of the floor vents (red) here as well:
View attachment 1788270