What ≅ means
Usually: these two figures are congruent. In geometry, ABC ≅ DEF says the triangles match exactly: same side lengths, same angles, so one could be moved, turned or flipped to lie perfectly on the other. The order of letters matters: A pairs with D, B with E, C with F.
In university algebra and other advanced maths, the same sign means isomorphic: two structures, such as two groups, are built the same way even if their elements look different. Some older books and physics notes do use ≅ for “approximately equal”, which is where the official name comes from.
Should I write ≅ or for “about”?
Write for rounded numbers. π 3.14 is the standard way to say “approximately”. Writing π ≅ 3.14 will be understood by most teachers, but a geometry or algebra reader may stop and wonder what is congruent. Keep ≅ for shapes and structures.
Pure maths notation, neutral and exact. It appears in textbooks, homework and lecture notes, not in casual chat.
Using ≅ for rounded numbers can be read as a claim of congruence.
Part of the collection
What it means when someone sends it to you
3 readingsThe figures are congruent: identical shape and size.
Don't confuse it with
5
Related characters
2
Combination ideas
3Worth knowing
- Number theory has its own “congruence”: 17 2 (mod 5) uses three bars, not ≅, so the same word takes two different signs.
Questions people ask
2Is congruent the same as similar?
No. Congruent (≅) means same shape and same size; similar () means same shape, any size.
Why is it called “approximately equal to” then?
The name records one older use. Unicode's own notes add “isomorphic”, and textbooks overwhelmingly read it as congruent or isomorphic.
More like this
18
≈Almost Equal To
=Equals Sign
△White Up-Pointing Triangle
∠Angle
≆Approximately But Not Actually Equal To
≊Almost Equal Or Equal To
≎Geometrically Equivalent To
≑Geometrically Equal To
≗Ring Equal To
≣Strictly Equivalent To
⩭Congruent With Dot Above
≃Asymptotically Equal To
≄Not Asymptotically Equal To
≒Approximately Equal To Or The Image Of
≌All Equal To
≖Ring In Equal To
+Plus Sign
<Less-Than SignHow to type or find ≅
- Also called
- congruent to · congruence sign · isomorphic to
- Search it as
- congruent symbol · isomorphic symbol · approximately equal · equal sign with tilde · \cong · ≅ meaning · geometry symbol
- Shows up in
- Anything that takes text · its shape is whatever your font draws
≅\2245Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.