定义一个弧或圆周上的弧长(不需要$r$的弧长测量)及其直接相加性

No explanations yet. Search for a related idea, or explore 圆和扇形的面积以及弧长.

Type a concept, like “slope” or “photosynthesis”.

↑ ↓ to choose · Enter to openSearch explanations and problems