I'm thinking the opening in the closest panel of the 2nd pic is maybe the chicken door, possibly upside down?I'd say the first pic is of the side panels (look like clean-out doors which should be at the bottom), the second pic is the back panel, and the third pic is the front panel (if that's a sliding pop door). The triangles are the gable ends that would go on top of whatever panels they fit, and there should be a couple of panels left for the roof. Just a guess...