teaa 2020-08-18T05:50:26+00:00 [img]https://img.nga.178.com/attachments/mon_202008/20/-7Q5-5gv0K1pT1kSgq-mb.jpg.medium.jpg[/img]如上图,大圆半径为小圆3倍,问小圆围着大圆转几圈能回到原点?