What 𝑟 means
A formula gives this letter a local role. Mathematical italic distinguishes a variable from ordinary text, but 𝑟 has no fixed value by itself. In an 18th-century geometry convention, Euler used lowercase r for the radius of an inscribed circle and uppercase R for the radius of a circumscribed circle; another formula can use r differently.
Mathematical italic for variables seems to have begun in European printing in the late sixteenth century. In 1999, scientific and technical publishers proposed encoding styled math alphabets separately so plain text could preserve distinctions important to formulas.
Why does 𝑟 become r?
NFKC can fold it to plain r.
When software applies NFKC normalization, this mathematical alphabet character becomes ordinary r. NFC keeps the distinction; NFKC can erase it from a formula.
For mathematical or technical notation; in ordinary prose, it can look decorative even though it remains a distinct character.
Do not assume it means radius without a formula defining it.
Part of the collection
What it means when someone sends it to you
2 readingsA math-style lowercase r with no fixed value supplied.
Don't confuse it with
1
Related characters
1
Combination ideas
1More like this
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How to type or find 𝑟
- Search it as
- italic r · fancy r · math variable · unicode italic · r symbol
- Shows up in
- Anything that takes text · its shape is whatever your font draws
𝑟\1D45FCodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.