There is not really a "length" of it, but you can consider how far you move if you move by a small ##\epsilon \hat \theta##, the length increases with the radius.
There is not really a "length" of it, but you can consider how far you move if you move by a small ##\epsilon \hat \theta##, the length increases with the radius.
Thanks. That makes sense. But why would the 'length' be r as Pavel Grinfeld says in the video.