That’s me.
I instantly recognized the circle & triangle signs with the figure icons in them cited in that wiki link by @Dewey_Finn. I’ve seen them thousands of times.
But I had never noticed that the circle always went with female and the triangle always went with male. It just never occurred to me. D’oh!
Seems to be common among such places. Chevys does pretty much the same thing.
Yet that same wiki link states that
“The three standard sex symbols are the male symbol
and the female symbol
, and the hybrid symbol ×. They were first used to denote the effective sex of plants (i.e. sex of individual in a given crossbreed, since most plants are hermaphroditic by Carl Linnaeus in 1751. The male and female symbols are still used in scientific publications to indicate the sex of an individual, for example of a patient.”
and that
Pedigree charts published in scientific papers now more commonly use a square for male and a circle for female
So, how often are you really seeing triangles, even in actual geneological charts?
Now I can’t help recalling associations like:
Most Hindu yantras include triangles. Downward pointing triangles represent feminine aspect of God or Shakti, upward pointing triangles represent masculine aspect such as Shiva.
Many mandalas have three concentric circles in the center, representing manifestation
so I daresay simple geometrical figures do not have any natural or obvious meaning that would enable someone to figure out whether one of them should be male or female.
ETA nor do Mars and Venus figures or any of the other abstract symbols considered in this thread, of course.
The only place I personally have seen any of this triangle / circle stuff is on restroom signs.
nevermind
Beat me to it. And it’s the first thing I thought of when I saw the thread title.
Even within chains they aren’t consistent. A chain I went to a lot opened a new restaurant near me. It took me three or four times going into the wrong bathroom to realize that everything was laid out about the same as the one I had been going to except the bathrooms were reversed
Might as well share an embarrassing story about what can happen when one gets confused over which door is which…
In the building where I once worked, 2 or 3 corporate jobs ago, we had an actual fitness center with weight machines, treadmills, stationary bikes, stair steppers, etc. I was accustomed to visiting about every other day in the mid afternoon, to wake myself up and stay in shape. One day, completely innocently, I was mentally going through the possible solution to a technical problem, and was pretty deep in my thoughts (which can happen when I exercise; it’s one more reason to do it). I turned left outside the men’s locker room door into the hallway and for some unknown reason, turned right…and into the women’s locker room.
Unfortunately I first realized my error when I got a glimpse of a large mirror across the locker room with the reflections of two topless women. I immediately turned around, saying “oops, sorry.” Fortunately I did not know or work with either of them, and could not remember much about what they looked like, tbh. But I do remember one of them said “Oh, my god…” as I turned around and hoofed it.
(In this case I did not realize I was entering into the women’s locker room because I didn’t even look at the little door label. But if I had been confused as to which was which, and visiting the lockers for the first time, this same event might have happened.)
Old joke from Reader’s Digest. Woman in a western-themed restaurant returns from trying to find the restroom and asks her husband: “George, which am I, a steer or a heifer?”
I’ve read that for outhouses, the one with a moon cut in the door (called the ventilator) was the Women’s. The Men’s used a star or a bunch of grapes.
Also secondhand - some countries in Northern Europe use 
for Women.
This so totally makes sense it isn’t even funny. I recall the bathrooms at (yet another) corporate job, this time over in Sweden, were single-use. This was an engineering company, and had about 50 to 60 employees working at this site, about 90% men. There were two bathrooms, helpfully labeled “Men” and “Women” (pretend it’s Swedish). But they were both single use, and so the women’s room was used mostly by guys too. Without any hesitation or shame. So they might as well have labeled both as “unisex” but for some reason did not. (Maybe it’s due to building codes.)
That actually caused me confusion as a child. It must have been the day my mom took me to register for kindergarten, because it was my first time in the elementary school building. The restroom doors were labeled “ladies” and “gentlemen”. I couldn’t read all that well yet – I knew the words “men” and “women” or at least what letters they started with, but “gentlemen” was a new word for me. But I knew “girls” started with ‘G’. So I figured that one must not be the one for me and used the other one. It wasn’t a big deal; no one else was in there, but after I cam out my mom informed me that I had used the ladies’ room.
They’re not even consistent within the office building I work in (or did back when I worked from the office). The ones at the front of the building near the lobby have the men’s on the left. The ones by the back stairwell have the men’s on the right. In the hallway out by the manufacturing floor the men’s is on the left again. That’s taught me to always look at the sign and not assume they’re arranged a certain way.
I don’t know why I’m finding so many ideas from reading this one thread…sorry if you’re getting sick of me 
Regarding the case of visiting “the wrong bathroom for my gender” when a young child, or when drunk, or when you’re in “absent minded professor” mode, I suppose you might not even know you’re in the wrong bathroom in some cases. For example, if you’re a guy and see nothing but toilets, that’s no biggie, it’s a unisex bathroom. But if you’re female and encounter urinals, then…you may be more likely to realize, immediately, that something went wrong.
Unless, of course, it’s a unisex bathroom with a urinal. Are these common?
Actually, for me at least, if I enter a restroom and I don’t see urinals, that would cause me to do a double take and double check that I’m in the right one.
There’s a large cinema near me that has two women’s rooms across the hall from each other. The first time I encountered this I saw the W on one wall and just headed across the hall without checking. Oops.
I don’t know whether they’re common; but I’ve known at least one case in which a restroom was converted from men’s to unisex without removing the urinal.
No, just no. A steer has been castrated. And a heifer hasn’t been bred yet, hence is virginal.
That just leads to all sorts of good retorts. (Technically, though, isn’t a heifer a cow that hasn’t had a calf yet? So it doesn’t have to be a virgin.)
Yup. She’s a heifer until she actually gives birth.
Illegal? On what grounds?
In which @LSLGuy learns that @WildaBeast is male. Not what I had thought.
Yes this. Unless it’s a one-holer in which case you look for the little lidded trashcan next to the stool.