How to type Perpendicular
To type Perpendicular (⊥), press Alt + 8869 on Windows, holding Alt while typing the digits on the numeric keypad, or write ⊥ in HTML. On any system you can copy it from this page, or enter its codepoint U+22A5 directly: Ctrl+Shift+U then 22a5 on Linux, or 22a5 then Alt+X in Microsoft Word.
Up Tack
- Copy it
- Unicode
- U+22A5
- Windows
- Alt + 8869 needs regedit
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 8869 | Above 255, so Windows will not accept it as typed. Copy the character instead. |
| Mac | N/A | Press the keys together. |
| HTML | ⊥ | Paste this into HTML source. |
| Unicode | U+22A5 | UP TACK |
Other math symbols
⊥ lives in the Mathematical Operators block (U+2200-U+22FF), the core set of mathematical and logical operators. Within Unicode it is classified as Sm, a mathematical symbol. Software may lay it out with the spacing an operator expects.
What Perpendicular is used for
In mathematical notation ⊥ is an ordinary symbol: it carries no special spacing and sits in an expression the way a letter does, standing for a thing rather than doing something to the things around it. That is the classification unicode-math gives it, and it is what decides how the symbol is set: $\bot$ in LaTeX, in maths mode rather than in a sentence.
Unicode publishes a second list of names for ⊥ in CLDR, the keywords its own search data offers rather than the formal name, and they are up tack, eet and falsum. Those words are what somebody looking for this character is liable to type when Perpendicular is not the name they know it by, and the search on the symbol lists matches them as well as the Unicode name.
What Unicode says about Perpendicular
The standard recognises ⊥ under another name as well: base, bottom. That is a formal alias, not a nickname, which is why it turns up in other people's documentation for the same codepoint.
The code chart points from ⊥ to perpendicular (U+27C2). These are the characters the standard thinks you might have meant instead, which makes them the ones worth checking when Perpendicular looks nearly right but not quite.
How Perpendicular behaves in software
⊥ is East Asian Ambiguous: one column in a Western locale and two in a CJK one. That is why a table that lines up on your machine can break on somebody else's, with no change to the text at all. It carries no direction of its own, so in a line that mixes English with Arabic or Hebrew it takes the direction of the text around it rather than forcing one.
What people ask about Perpendicular
How to insert perpendicular symbol in word?
In Word, type 22a5 and press Alt+X, which converts the codepoint you just typed into ⊥. Insert › Symbol › More Symbols finds it by its Unicode name, UP TACK. Google Docs has no Alt+X, so use Alt + 8869 there, or Insert › Special characters and search the same name.
Every way to write Perpendicular
| Form | Value |
|---|---|
| Codepoint | U+22A5 |
| Decimal | 8869 |
| UTF-8 bytes | E2 8A A5 |
| UTF-16 bytes | 22 A5 |
| HTML entity | ⊥ |
| HTML numeric | ⊥ or ⊥ |
| CSS | \22A5 |
| JavaScript | \u22A5 |
| Python | \u22A5 |
| URL-encoded | %E2%8A%A5 |
| LaTeX, in maths mode | $\bot$ |
| SVG | 22A5.svg · (SIL Open Font License) |
If ⊥ arrives as ⊥
One character has become three, which is what a three-byte UTF-8 sequence looks like when each byte is read separately: E2 8A A5 read as Windows-1252 gives exactly ⊥. The text is intact and the damage is in the reading, so setting the reader to UTF-8 restores it and retyping does not. A rectangle instead of the mojibake means the opposite: the encoding is right and the font has no glyph at U+22A5, which for a character this far outside Latin-1 is common in older office fonts.