South African Skeptics

For our resident math geeks

Offline brianvds

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I'm having an attack of stupid again. Can somehow tell me how one goes about to determine the size of angle a in the below diagram?



Offline Mefiante

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As given, the diagram contains insufficient information to determine the angle a because the orientation of line segment EG can be varied independently of that of line segment FH.

Still, it appears that the line segments EG and FH are reflections of one another through a line that is perpendicular to the parallel pair of line segments AB and CD.  If this assumption is correct, then:—
  • By symmetry, the angle of intersection between EG and CD is also 70°;
  • By parallel translation, the angle of intersection between EG and AB is also 70°; and
  • Therefore, a = 180° – 70° = 110°.

'Luthon64
"Sensitive" people are now carefully examining the entire universe, trying to find something to be "offended" at. It won't stop until such time as the "offenders" learn to stop apologizing, and saying "freck off" instead. — brianvds, The ShoutBox Classics, 02/07/2018.


Offline brianvds

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Ah well, then perhaps I wasn't all that stupid after all. The problem was in a grade 8 math assignment that I was helping a kid with, and it frustrated me that I couldn't do it either. :-)

Well, there is a memorandum somewhere. I'll go check what their supposed solution is and come report back. Perhaps they meant to indicate a symmetry or something. I have noticed that their memoranda sometimes contain information not given in the original problem.

The browser spell checker tells me 'memoranda' isn't a word, and that perhaps I was trying to type Andromeda. I'm glad it doesn't have an autocorrect function. Particularly since it tells me 'autocorrect' isn't a word either. :-)


Offline Mefiante

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Interesting.  In that case, bacteria, media, momenta, quanta, fora and many more shouldn’t be words either…

(There, I’ve subverted your thread.  Now it’s for our resident word geeks. )


'Luthon64
"Sensitive" people are now carefully examining the entire universe, trying to find something to be "offended" at. It won't stop until such time as the "offenders" learn to stop apologizing, and saying "freck off" instead. — brianvds, The ShoutBox Classics, 02/07/2018.


Offline brianvds

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Interesting.  In that case, bacteria, media, momenta, quanta, fora and many more shouldn’t be words either…

(There, I’ve subverted your thread.  Now it’s for our resident word geeks. )


'Luthon64

Let me quickly check whether math and maths are words. Verdict: spell checker is fine with both. But not with mathemagics. :-)


Offline st0nes

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Interesting.  In that case, bacteria, media, momenta, quanta, fora and many more shouldn’t be words either…

(There, I’ve subverted your thread.  Now it’s for our resident word geeks. )


'Luthon64
When speaking or writing English, I prefer to use the English plural form, i.e. memorandums, forums, &c. I haven't so much as glanced at a Latin textbook since the hell-days at school more than half a century ago, so I'm very unsure as to the correct Latin plural, or whether a word does indeed have a Latin root or the Greeks have stuck their oar in somewhere. Rather than look like an idiot by using something obviously wrong--virii is emphatically NOT the plural of virus--it's easier just to use English.
Tempora mutantur, nos et mutamur in illis

Outside of a dog, a book is man's best friend. Inside of a dog it's too dark to read.--Groucho Marx


Offline Spike

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Greeks have stuck their oar in somewhere.

If there are Greeks around sticking anything in anywhere, let's hope it's Bacchus

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Offline Rigil Kent

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Bacchus is proudly Roman ... or at least, he is Roman without necessarily giving a toss about being Roman.

You know it's cold outside when you go outside and it's cold.


Offline brianvds

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Bacchus is proudly Roman ... or at least, he is Roman without necessarily giving a toss about being Roman.

He's probably too drunk to remember where he fits in. What was the ancient Greek version again? Dionysus or something?

The Ancient Greeks invented gods. The Ancient Geeks invented math.


Offline Spike

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I know who/what Bacchus 'is' - but what a priceless painting. With that face, he could be sticking in anything, anywhere, anytime, and he would be having the best time ever!

But, this does bring up an interesting point (cross-referencing another debate about mathematics in SA schools).

* How many of us received more than even a basic mention of the various pantheons in school?
* Can anyone still be described as having received a 'classical education'? (I am genuinely curious about this - in older books, such a description was often used in characterisation)


Beware the pod-people.


Offline BoogieMonster

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* How many of us received more than even a basic mention of the various pantheons in school?

I was kinda difficult to go into it what with "them" being false gods and "our" god being the "true" one, after all.

"Monkey killing monkey killing monkey over pieces of the ground, Silly monkeys, give them thumbs, they make a club and beat their brother down. How they survive, so misguided, is a mystery. Repugnant is a creature who would squander the ability to lift an eye to heaven, conscious of his fleeting time here" - Tool