In geometry, I can use Hatch Marks to indicate 2 lines have the same length. It is very useful and clear to most people.

How can I do the same for area? Is there a different notation for that? e.g. I have a rectangle and a triangle and I want to indicate they have equal area.

  • 3
    $\begingroup$ You can use the same color. $\endgroup$ Aug 1, 2017 at 23:58
  • $\begingroup$ I've considered using concentric circles, in a manner not-unlike hatch marks. Alternatively, circles with hatch marks inside them (which, basically, makes them look like simple Roman numeral labels). I can't say that I've seen these in use. Shading same-area with the same color (or monochromatic textures) can work. (Ah, @Salahamam_Fatima beat me to that suggestion as I was typing! :) If the areas overlap, some of these approaches could be hard to read. $\endgroup$
    – Blue
    Aug 1, 2017 at 23:58

1 Answer 1


As far as I know there is no standard method to indicate equal areas. The comments have already mentioned some good ideas, but to add one more, a simple (and maybe uncreative) method could be to label the interiors of each shape with a (probably capital) letter: Same letter, same area. If you already have lots of points and/or angles labeled with letters, you could perhaps surround an area-indicating letter with [brackets] to help differentiate it.

But whatever you do, be sure you tell your audience the method you're using beforehand. You should always do that whenever you introduce new notation.


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