For more information, see a very similar design here by Zookeeper15133 at BackyardChickens.com
Slots are cut all at one time to make sure they all line up.
After the saw cut, use a wood chisel to remove the slot.
Setting up the apex.
Gusset plate screwed in place
Marking the angle for cutting.
Apex ready to receive the ridge piece
Apex showing gusset plate
Building a Chicken Ark – Part 2