For the question at the end the circumference would be 32 pi or 100.6 CM. Also I decided to solve the area cuz I felt like it and it’s, 256 pi or 804.2 CM. Thanks so much for helping btw! I was struggling so much because my math teacher doesn’t explain things well.
Good luck trying to conquer this ring when it takes light billions of years to travel the circumference. If Earth was made into a Halo ring this size and you looked straight up to see whats going on, you'd see a time in Earth's history before even dinosaurs existed.