What ∠ means
∠ is the angle. Unicode classifies it as a mathematical symbol and files it in the Mathematical Operators block; this site shelves it under Maths.
Its appearance depends on the font and text styling.
How it is encoded
∠ is a single code point, U+2220. In HTML that is ∠, and in CSS \2220.
Don't confuse it with
4Questions people ask
1Why does ∠ show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type ∠
∠\2220Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.

