# Symbol for the area of a shape

There are mathematical symbols to represent angles ($\angle AB$) and magnitudes ($|AB|$) and what not (ie: not variables, but rather symbol operator thingies).

Is there a symbol to represent the area of a given shape?
(so for a shape defined by points $A,B,C,D$; I could represent the area as *symbol* $ABCD$ or something to that effect)

I'm not looking for a variable to contain the area, like $A$, but a representation for a given shape.

Thanks!
(Sorry if this question is out of place; new here)

Whatever notation you use, define it, and everything should be fine. To get you some ideas, you could use, for example:

• $[\triangle ABC]$, $[\hspace{-1pt}[\triangle ABC ]\hspace{-1pt}]$,
• $\langle \triangle ABC \rangle$, $\langle\!\langle \triangle ABC \rangle\!\rangle$,
• $|\triangle ABC|$, $\|\triangle ABC\|$,
• $\mu_2(\triangle ABC)$.

If you won't use other measures like lenght or volume, you can skip the "2" symbol or the double brackets.

I hope this helps ;-)

The Lebesgue measure seems like what your'e looking for. It is a generalization of the well-known length, area and volume.

For the area of the shape ABCD, you could write $m(ABCD)$

• It seems fairly general. Should one declare the specific meaning (eg: n = 2) or is that implied from the argument of m (ABCD seemingly representing a surface)? – Anti Earth Apr 7 '13 at 9:49
• ... or $\mu$ or $\lambda$ instead of $m$. And then one would expect $ABCD$ to denote the set we want to find the area of. So there's a bit of abuse of notation involved. In other words, there's not really a standard notation as such. You'd better introduce any notation and symbol you want to use for this purpose in your texts ... – Hagen von Eitzen Apr 7 '13 at 9:50
• If you want to talk about two dimensional shapes in the plane, you should say "the two-dimensional Lebesgue measure". – user1337 Apr 7 '13 at 9:59