In my culture, rhombus is the basis of a vagina pictogram. In my culture, rhombus is every schoolboy’s favorite shape.
https://commons.wikimedia.org/wiki/Category:Czech_vulva_symbols
Pica in brazilian Portuguese means dick.
Pičivo.jpg
That one was great 🤣
Every square you ever met is a rhombus that gave up its art career and got a boring 9-5.
This person hasn’t done math past elementary.
I went up to Calculus I in college (along with some physics and engineering), and I’ve done a bit of amateur math outside of school … but the concept of a rhombus was still used exactly zero times.
The engineers prefer triangles, the physicists prefer circles, and the pure mathematicians are usually dealing with weird shapes that don’t even have names. Who uses the rhombus?
What is a rhombus but two triangles, my dear
They’re not really mentioned in more advanced math. It’s all polygons.
Ok, triangles are often treated as a special case. But for anything else it’s a n-sided polygon.
You mean regular polygons. A rhombus is an irregular polygon. Triangles are also all polygons. An equilateral triangle is a regular one.
Nah in my experience everything is a circle. You see π even in places you don’t expect
It’s not even doing math, just watching science videos etc. is enough to hear the word every now and then. This is surely a person who has no interest in learning overall.
Don’t forget the poor trapezoid.
RIP
Some pretty rhombus logic if you ask me
RhombusMake it higher so it could qualify
Shit you are right, it’s just a parallelograyhound
If I ever have my own home, my house will have a rhombus room.
“Don’t you mean a rumpus room?”
Bro, that’s not even a real shape.
clearly you didn’t learn, since diamonds are a pretty common shape
Haven’t you guys used a kite before?
Every 3 ft square box that you shoved a bunch of 3.25 ft long irregularly shaped items into then closed the flaps on is a rhombus.
It’s also called diamond or zoomie square. You know, cuz it’s like a square that’s going so fast the pointy parts start at the tippy top
oh they don’t appear again, but its generalization, the parallelepiped, does:
it’s used to calculate volumes of curved objects. basically you chop down the object into a lot of small parallelepipeds (mentally), and then calculate the volume of each of them small things and sum over them. Done.
to calculate the volume of a parallelepipede, there’s a surprisingly simple mathematical formula. If you have the vectors for the three sides a, b, c, then the volume V = (a × b) · c, where × is the cross product and · is the dot product. it’s very simple and an effective way to calculate volumes of curved / deformed objects.
Links:
- (german) https://de.wikipedia.org/wiki/Transformationssatz
- (english) https://en.wikipedia.org/wiki/Integration_by_substitution#Substitution_for_multiple_variables
where × is the cross product and · is the dot product
pardon my ignorance but what the fuck is a “cross product” or a “dot product”? I assumed at first this was multiplication, but then I saw the dot and realized this isn’t anything I’ve ever been taught
https://en.wikipedia.org/wiki/Cross_product
https://en.wikipedia.org/wiki/Dot_product
sorry i am too tired to explain in full detail rn
that’s fine, and thanks for the links! I just don’t quite agree that this is suprisingly simple mathematics :P
yeah it’s “surprisingly simple” in the sense that there’s a well-defined algorithm to do it. a computer can do it easily, with very little time/effort. anyways, you don’t need to think about every problem specifically. “now i got this parallelepiped, how do i calculate the volume?” you can just use the same formula every time.
it’s used to calculate volumes of curved objects. basically you chop down the object into a lot of small parallelepipeds (mentally), and then calculate the volume of each of them small things and sum over them. Done.
For anyone not quite getting this (like me), to calculate the area under a curve in 2D we were taught to cut it into tiny thin rectangles and sum those up; intergration when those rectangles have a width tending to 0.
For 3D (e.g. a pond ripple) or higher curves, a simple rectangle wont cut it as the length of the rectangle might only get the top of a wave, but not capture the crest of it tangential to it. So you create slopey rectangles to approximate that space, and bring the limit to zero to get the area (I think).
My only confusion now is, if I’m deforming a rectangle from one side to approximate the curve just above it, am I not also deforming the bottom of that rectangle in the same way (for the parralel strcture to hold true), and creating a forgotten space just above the axis plane?
well, almost. it’s a bit different than that.
what you mean is this:
you approximate an integral with a lot of small thin rectangles, but if the curve’s not entirely rectangular, there’s gonna be some error, which becomes smaller as the rectangles become smaller. this can be ignored if the rectangles are thin enough. and it’s not what i meant.
what i meant is something like this:
you take a piece of elastic fabric, and paint some squares on it. now, if you stretch the fabric, the squares change shape, they become approximately parallelepipeds. this is a good approximation. now, if we want to calculate the total area of that fabric (after stretching), we can calculate the area of each of the small parallelepipeds (which is easy to do with the formula in above comment) and then sum them.
Ohh! Calculating area, not volume under the curve – I see, thank you
When I played “Psychonauts: In the Rhombus of Ruin” I got reminded again that this thing actually exists.
Rhombuses are really commonly used in trigonometry puzzles. You know, “Here’s a bunch of lines and a couple of angles, find the angle at X.”
