circle

1 - Aristotle considered that the stars must move in circles because the circle is the most perfect curve.

2 - Copernicus inferred that the earth and all the planets circle the sun.

3 - The geometry of the straight line and the circle goes back to the ancient Egyptians and Babylonians, but it was only with the ancient Greeks that geometry was developed as a logically organised field of study.

4 - Snowy owl habitat spans over the cold regions near the Arctic Circle, which are typically characterized by scarce vegetation and dense snow cover.

5 - We have the same circle of friends so there were times that we hang out together.