No. Any great circle on the earth has a circumference of about 24,000 miles. The circumference of the Arctic Circle (and the Antarctic circle too) is about 9,945 miles. Imagine circles around the North Pole. The closer to the pole the circle is, the smaller it is. If you were right there at the North Pole, you could walk a 10-foot circle around it. The Arctic Circle is a circle around the pole, but about 1,570 miles south of it. The only circle around the pole that's a great circle is the Equator.
No. The only line of latitude that is a great circle is the equator. Incidentally, any pair of longitude lines 180 degrees apart from each other would form a great circle.
Arctic circle
Great Bear Lake is on the Arctic Circle in the Northwest Territories.
Partially.
Great Bear Lake
No; neither of the tropics is a great circle. The only line of latitude that is a great circle is the equator. The arctic and antarctic circles are not great circles, either.
It is south of the Arctic circle.
Great Bear Lake
The Arctic Circle passes through the Arctic Ocean.
Great Bear Lake
Great Bear Lake
The Great Bear Lake
The Arctic Circle is at 66 degrees 32 minutes N latitude. Everything north of the Arctic circle is considered to be the Arctic.