Introducing Basic Stroke
The final basic stroke, quān, which means “circle,” isn't in current Mandarin usage. Older versions of the Chinese language used the quān stroke.
For example, the oldest known version of the character representing the word for “sun” was a circle. Over thousands of years, this character is now standardized in modern Chinese as 日 (pronounced rì in Mandarin).
Even so, the basic stroke quān is included here for the sake of completeness.