Don’t the internal angles need to be 90°? Two of those right angles aren’t right angles on the inside.
Okay, calm down Diogenes
The interior angles need to be equal 🤓
Straight lines. Also two sets of parallel lines. This is one definition of a square, but not the common one.
I believe these lines are straight with a black hole at the centre.
straight, gay, lines are lines. let them be.
If that’s so, the angles are probably not right angles.
None of the angles looks wrong either
This shape could exist as a projection onto an upright cylinder, wrapping around the cylinder. The two straight edges go vertically along opposite sides of the cylinder. The curved lines wrap around the circumference. The lines are now straight and parallel on the net of the cylinder.
But we can go further: Imagine taking this cylinder and extending it. Wrap it into a loop by connecting the top to the bottom so it forms a torus (doughnut) shape. This connects both sides of the shape, now all “interior” angles are on the inside of the square, and all “exterior” angles are on the outside. The inside and outside just happen to be the same side.
Can straight be defined in a nonlinear environment?
I would guess on a sphere these can be straight yes: The pole goes into the center of cicular thing and radius of the sphere needs to put the other arc on one latitude.
Euclid’s first postulate: Give two points, there exists exactly one straight line that includes both of them.
Counterexample: North and Southpole on Earth.
This only applies in 2nd order real space. Euclidean geometry aside, I agree with at least one line could exist between two points
If it clucks likes a chicken and scratches like a chicken, it’s Man.
I got that reference!
Behold, a featherless biped!
And for those who don’t: Plato, a Greek philosopher, was putatively asked by a student while teaching at the Academy what the definition of a man (human) was. Plato responded that a man is a “featherless biped”.
Diogenes, another Greek philosopher and infamous quick-wit, caught wind of this and thought that was the dumbest thing ever, so he gate-crashed one of Plato’s lectures and pulled out a chicken which had all of its feathers plucked out and said “Behold, a man!”.
Someone never had to deal with mathematical proofs, only layman’s definitions.
All properties of a parallelogram apply:
- Opposite sides are parallel
- Opposite sides are congruent
- Opposite angles are congruent
- Consecutive angles are supplementary
- Diagonals bisect each other
AND
- All angles are congruent
- All sides are congruent
- Diagonals are congruent
- Diagonals are perpendicular
- Diagonals bisect opposite angles
Of course, but such strict definitions only come about because smart people come up with examples like OP when you don’t add the full definition.
Learned this one in 6th grade geometry: drawing a square in thr corner doesn’t make it 90°
drawing a square in thr corner doesn’t make it 90°
No, it doesn’t, but it does mean that, for the purposes of your 6th grade geometry question, you can assume the angle is a right angle. Even if it visible looks like 45°, if they put a square there, that’s 90.
More to the point though, a radius of a circle always meets the circumference at 90 degrees. All the squares in this problem are doing is telling you “this line, if it were continued, would be the radius of the incomplete circle”.
But these are all right angles, as long as the two arcs are centered on the same point as the intersection of the two straight lines.
The Diogenean Theorem
Solution:
Explanation:
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in order for the straight lines to be 90 deg with the circles, they must be radii of circles with same central point
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the length of an arc is defined as c = r * θ (where r is the radius, and θ is the angle)
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we define the inner circle with radius r₁ and its arc L₁ = r₁ * θ₁
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we define the outer circle with radius r₂ and its arc L₂ = r₂ * θ₂
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Because of (1), θ₁ + θ₂ = 2π
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To create the shape, L₁ = L₂ = r₂ - r₁
If you start replacing and solving, you will get a 2nd grade quadratic, which has a positive and a negative solution. The positive solution is that magic number.
Why point (5)?
Since the straight lines are radii, they cut the circles at angle θ and 2π - θ, respectively. Adding those, you get 2π.
Okay, but… Why? Is that a theorem that I don’t remember from school?
Take this shape as an example. The “square” in question consists of AC, BD, the outer AB, and the inner CD.
Point (5) means that, since the lines AC and BD are radii of the concentric circles, the arcs AB and CD should have the same inner angle. That’s because the angle COD is equal to AOB.
Since, the inner angle is the same, then the outer AOB should, by definition, be 2π - (the inner AOB), because that’s how radiants work; a circle is 2π rads.
Thank you! But why arc CD and arc AB length should add to 2 PI? Or why does the angle COD times two is 2PI if that’s what you meant?
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People are taking c/Memes a little too seriously
Dammit Diogenes, this is why we don’t allow you in the geometry class anymore.
Coincidentally also the logo of [email protected].
Or the outline of a shot put area
Wow
I get downvoted for bringing it up, but for fuck’s sake you’re dumping literally everything into this community regardless of the fit. There are a dozen (I’m estimating) other communities that could benefit from the content you post but you have thus far insisted on only posting here.
Can you at least make the tiniest effort to spread content to other communities that would benefit from the increased views and potential subscriptions?
I shall await the fun police and everything’s a meme comments.
Thank you for calling it out. Had a look at post history and I agree, blocked. Lemmy is attracting all sorts of random noise lately.
Dumb question but wasn’t there a cross-posting button so you can spread this meme to other communities?
At least it’s better than endless American politics.
I’m sure there are more than a dozen and you are right. I’m still trying to get the hang of the whole fediverse thing, but so far most of the more niche communities I have tried to interact with are on different servers not federating with each other? Or maybe I’m doing something wrong? Not sure about that one. Also not sure if cross-posting works. I mean I know it works, but do those posts federate correctly? Can other fediverse apps see them correctly?
I thought your post was funny
I thought it was funny, but maybe they have a point? I didn’t even realize I was on the memes community, I just assumed this was on lemmyshitpost. I guess it’s a stretch to call this joke a meme.
Honestly I have no idea what should and shouldn’t be called a meme. In my friend groups this definitely qualifies as a meme, but lemmy is way bigger than my bubble so 🤷.
The best any of us can do is adjust based on feedback I guess.
The [email protected] community fits great for this post.
A square must also have two pairs of parallel sides.
No it doesn’t. Right angles + equal length is a sufficient condition
No, it isn’t. A square is a plain, convex and regular quadrilateral with four internal right angles.
In that case, there’s no need to specify anything about the angles. Or, the characterisation the meme is playing with: a shape with four straight sides of equal length and right angles. Adding parallel to the meme’s version doesn’t help.
I’m just tired of this thread. Not only do Lemmy users have this weird urge to show off their high school maths knowledge to dunk on a joke that obviously only works because OP played with the definition, but they’re not even correct. The /r/mathmemes thread was much better.
✌️
Calculus can find you two pairs of parallel sides, right there on the circle!
Does no one understand this is a joke, talking about parallel lines and mathematical proofs is pointless when its a fucking meme
These are parallel too. They just look that way because they are project on to the euclidean plain.
Its wrong though so the joke falls flat
Didn’t realize jokes have to be literally correct
Just the good ones.
Or the fun part.
You’re having fun wrong!!1one
We do understand it’s a meme and a joke. Just not a very good one, because one can easily poke holes into it.
Just not a very good one, because one can easily poke holes into it.
That’s not how jokes work.
Depends on the joke.
No, it depends on if you have humor. Yes, humor is individual, I know. But people without tend to over analyze and try to pick the joke apart, often missing the point.
A joke doesn’t have to pass every technicality. You thinking it’s bad if it doesn’t, only applies to your humor (or lack there of).
Ooh, watch out, the humor police is here! Everything the deem funny is humor and if you don’t find funny what they do you don’t even have humor! Wee-ooo wee-ooo!
I can be presented with a bad joke without the urge to pick it apart. You couldn’t. Just saying.
And you cannot take criticism. Just saying.
(Also, I’m not picking apart the joke, I’m explaining why some people do.)
Its supposed to be absurd, taking it seriously makes the already bad joke even worse
It’s not about taking it seriously. The meme wants to be a technically correct-meme, where a thing fulfills another things definition and thereby could be deemed the other thing - which creates the absurdity the meme lives off of. But in order for that kind of humour, there cannot be obvious holes in the logic of the joke and these obvious holes are very present in this meme.
Well the text in the image of the “definition” of a square is clearly tailored to fit this joke, thats why the logic of what a square actually is doesn’t apply. Its like telling Diogenes that his chicken is not technically a human because it doesn’t have two hands and a nose.
Diogenes plucked that chicken to point out Platon’s definition of a human (being a bipedal, featherless animal) being flawed. This meme leaves out parts of the definition to enforce a joke. Two different situations.
Its similar enough, the definition is limited and therefore enables a joke to be made.
It’s not similar, it’s the exact opposite.
Any maths joke of this type will have obvious holes in it, that’s just how maths works
It’s not pointless because you can laugh about a joke and then learn something about math.
They don’t cancel each other out. They can be at the same place and still work on their own.
I love memes that are funny on their own, but also provide discussion material.
