2021年7月19日
Something FUN!!! (geometry)
摘要： Let $r_1$ and $r_2$ be the radius of two concenter circles with $r_1<r_2$. Point $A$ is moving at constant speed on the circle with radius $r_2$, and 阅读全文
posted @ 2021-07-19 12:11 Corylus 阅读(56) 评论(0) 推荐(0) 编辑