Circle Geometry Proofs (1 Viewer)

qwerty44

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Im not having trouble with proving stuff, but rather writing the proofs for each theorem. Im not sure what to write for each one. this may sound dumb but I can't afford to write out the whole theorem, and I cant be too brief...fussy teacher.

So what should I write for each theorem?

For example: The exterior angle of a cyclic quadrilateral is equal to the opposite interior angle.

Do I write out the whole thing, or just "exterior angle of cyclic quad."??
 

funnytomato

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you may be able to get away with shortening the theorem, but how brief is too brief ?

I think it's too hard to say, so I'd probably write down the whole thing
 

Aysce

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Im not having trouble with proving stuff, but rather writing the proofs for each theorem. Im not sure what to write for each one. this may sound dumb but I can't afford to write out the whole theorem, and I cant be too brief...fussy teacher.

So what should I write for each theorem?

For example: The exterior angle of a cyclic quadrilateral is equal to the opposite interior angle.

Do I write out the whole thing, or just "exterior angle of cyclic quad."??
Hmm, in that case I would write out:

Exterior angle of quadrilateral equal to opposite interior angle.

Basically just say it as long as it makes sense but briefly. Don't worry if the one I listed has no "The" since it's maths, not english.
 

qwerty44

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many books use this kind of abbreviations, which looks fine to me
as long as you don't get a fussy teacher marking your assessments, or in the HSC

I'd use the abbreviations in practice ,but remember what the full version is
and use that in real exams
Your probably right, no point risking it. Thanks
 

deswa1

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You should do whatever your teachers want. I know at Tech, we can't write alt. ∠s, // lines, but rather have to write alternate angles on parallel lines. If we wrote the former, we'd lose marks so basically check with your school. Do whatever in the HSC though.
 

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Carrotsticks

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In one of my earlier Preliminary exams, one of my reasons was "External Angle" and I shortened it by writing "Ext. ∠"

I lose a mark there and the teacher circled my reasoning and wrote "Exterior Angle? Extension Angle? Extravagant Angle? What does 'Ext.' mean?" and I found out the hard way that my school did not like these shortcuts.
 

Drongoski

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I feel the teacher was a retard. In the given context 'ext' is well-understood to mean 'external' or 'exterior' as the case may be. In the given context, how could 'ext angle' ever possibly be confused for 'extension angle'[no such thing]or 'extravagant angle'? Still,to you students out there, just to be on the safe side, do as you are told.
 
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such_such

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You should do whatever your teachers want. I know at Tech, we can't write alt. ∠s, // lines, but rather have to write alternate angles on parallel lines. If we wrote the former, we'd lose marks so basically check with your school. Do whatever in the HSC though.
+1

Your schools marks it so you should listen to them.
 

qwerty44

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The abbreviations provided are fantastic and should be sufficient. However some teachers do not allow some such (e.g. deswa1's)) and I disagree with them.

But your "ext angle of cyclic quad" is not good enough. Point is: "what about it"? You should complete it with, say, "= int opp angle"
That answers my question, as I wasn't sure if we just say enough to identify the theorem, or say most of it. That said, our teacher accepts: "∠ in alternate segment".
 

qwerty44

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In one of my earlier Preliminary exams, one of my reasons was "External Angle" and I shortened it by writing "Ext. ∠"

I lose a mark there and the teacher circled my reasoning and wrote "Exterior Angle? Extension Angle? Extravagant Angle? What does 'Ext.' mean?" and I found out the hard way that my school did not like these shortcuts.
Lucky it was prelims...
 

unLimitieDx

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I think if i remember correctly you can write circumference as a circle with a dot in the middle and with a ce next to the circle
 

theind1996

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In one of my earlier Preliminary exams, one of my reasons was "External Angle" and I shortened it by writing "Ext. ∠"

I lose a mark there and the teacher circled my reasoning and wrote "Exterior Angle? Extension Angle? Extravagant Angle? What does 'Ext.' mean?" and I found out the hard way that my school did not like these shortcuts.
TY for letting me know.
 

RivalryofTroll

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I think if i remember correctly you can write circumference as a circle with a dot in the middle and with a ce next to the circle
Really? To be honest, when it comes to proofs, just NEVER take short cuts and write down your proofs down properly to be on the safe side.

Good habit for the HSC as well.
 

Sanical

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In one of my earlier Preliminary exams, one of my reasons was "External Angle" and I shortened it by writing "Ext. ∠"

I lose a mark there and the teacher circled my reasoning and wrote "Exterior Angle? Extension Angle? Extravagant Angle? What does 'Ext.' mean?" and I found out the hard way that my school did not like these shortcuts.
That was probably general nit-picking. I don't think you'd lose that mark in HSC.
 

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