Respect the Parallelogram

Here’s a tweetstorm that demands respect:


And now the storm:

  • First: don’t disrespect geometry and don’t effin disrespect parallelograms – particularly IN a parallelogram…
  • The SIGN is a parallelogram (rectangle) as is the WINDOW. Structurally the building is held up with triangles & parallelograms…
  • The graphic software used to MAKE the sign contains maths that deals with vectors & hence PARALLELOGRAMS…
  • EVERY season is PARALLELOGRAM season if you live in a built environment or use technology. I’m bloody glad I learnt about parallelograms…
  • Imagine if I’d spent my time learning about taxes at school instead of parallelograms…
  • 1 it would all be out of date now & 2 be about the wrong country & 3 be so vague as to be irrelevant to my current life.
  • Oh & 4 be as dull as shit. Whereas geometry is truly amazing…
  • …now no offence to accountants in general. I admire all maths related disciplines & accountants are unfairly maligned as dull…
  • BUT don’t shit on a different field of maths for cheap laughs…
  • ‘But it is just a joke’ no it is a shitty joke that perpetuates a shitty idea: that only ‘useful’ maths is worth learning.
  • ‘Useful’ is a shitty standard for general education. Drama, literature, art, music we learn because they are good in themselves…
  • ‘Oh but STEM is different!’ No! Name a dinosaur – go on. I bet you can name several correctly with the right technical name…
  • …how come? Most people will never need to deal with actual dinosaurs. But we learn about them because they are FUN and weird & freaky…
  • People who succeed in maths & related areas find pleasure in maths. ‘Useful’ has its place but it is not as powerful as pleasure.
  • …and tying down a subject whose power is its abstractness with ‘useful’ means that it will always fail…
  • ‘When will I use this’ I don’t know because you haven’t lived your life yet!…
  • Anyway. Moral: don’t disrespect parallelograms.

Quite so. The problem with parallelograms is that they’re a con. They tell you that finding the area is simple: it’s base · height. Easy peasy!

But what’s the height? Crap. The length of the sides isn’t enough to figure that out. You need to know the angles too. And then you have to apply some trigonometry:

So there you go: the area of a parallelogram is a · b · sin α. Greek letters! Blecch. So sure, respect the parallelogram, but only because such a simple looking thing requires more math than you’d think to figure it out.

No worries, though. You’ll need it when you take physics anyway.