Number 13, I never even thought about. The shapes of two countries being alike are a coincidence. Maybe the argument was, they were results of the same geological events, they are not coincidences. Either way, so what? Not a bone I would bother to pick. Some people, be they student or teacher, cannot handle being told that they are 100% WRONG!
At one time there was one continent on the earth. It split into the continents we know today. South America and Africa were together.
I pointed out #13 when I was in grade school. I got the same response from my teacher. It wasn’t until years later when I read about Pangea.
In a college psychology class, they taught about the Tasaday tribe in the Philippines. I pointed out it was completely fake and by then even National Geographic admitted it. That day I got a fail on a test that should have been an A. From that point on I just gave the professor what he wanted to hear and took my A on everything.
Not a coincidence by modern thinking. Pangea and plate tectonics are the terms you need to delve into.
Understanding complex geological features in Africa and then reapplying that insight in South American has led to discovering and now producing billions of barrels of crude in Brazil.