Is there a reflex angle symbol?
I only knew this angle symbol "$\angle$", which is usually used to represent acute angles. But now I have accounted a problem, where I wanted to represent the reflex symbol of $\angle ABC$.
I know, I can simply say "The reflex $\angle$ of $\angle ABC$" or "2$\pi$ - $\angle ABC$", but is there a symbol for reflex angle, just for interest?
$\endgroup$ 22 Answers
$\begingroup$If allowed to handwrite (or in this case to use a drawing software), I would use something similar to $\large ABC$. Not sure if this is standard notation or if there is some $\LaTeX$ glyph for that.
The point is that you can invent the symbol you want and use it consistently... the only two matters are
- Is it clear? In case of doubt define it and problem solved.
- Can I typeset it? In this case there are always workarounds.
This question has always concerned me. To my knowledge: no, there isn’t.
Unicode has angle ∠, right angle ∟, and oblique angle ⦦, but nothing for reflex angle.
$\LaTeX$ has angle $\angle$ and (wide)hat $\widehat{B}$.
Just today I taught my students that $\angle ABC=A\widehat{B}C\leq180$ and if you want to refer to the larger angle at the vertex you literally just say/write reflex $A\widehat{B}C$. I think reflex $\angle ABC$ is a little contradictory but if you imagine an “of” then it makes perfect sense—reflex of $\angle ABC$.
One of my students suggested $A\check{B}C$ which I think is genius. But it’s only good if you’re already using the (wide)hat $\widehat{B}$ notation.
My advice (currently) is to assume $\angle ABC$ or $A\widehat{B}C$ is oblique (acute or obtuse) and specify reflex $A\widehat{B}C$ or reflex $\angle ABC$ if you need to.
It doesn’t feel like a satisfying answer but it’s the one I’ve decided to live with.
EDIT
\widecheck looks better for the upside down hat but doesn’t render here on SE.
