How to combat the bothersome incircle construction inaccuracy? - boards.ie

 24-05-2012, 14:03 #1 reznov Registered User     Join Date: Jan 2012 Posts: 920 How to combat the bothersome incircle construction inaccuracy? I have trouble constructing a perfect incircle which doesn't go past the three sides of a triangle. Always a part of the circle will jut out and it's an eyesore as i strive to develop a professional representation of my mathematical ability. Will I lose many marks? How do you construct a sexy incircle?
 24-05-2012, 14:10 #2 JeaicMaG   Join Date: Feb 2012 Posts: 787 You should be able to judge it by eye.
 24-05-2012, 14:11 #3 reznov Registered User     Join Date: Jan 2012 Posts: 920 Just a little bit always goes astray. I'm aiming for that Maths certificate and don't want the chief examiner to get the wrong impression. I do it by eye! Maybe I need an eye replacement?
 24-05-2012, 14:16 #4 cutty9 Closed Account   Join Date: May 2012 Posts: 61 you need optilase. if you can't get the incircle construction fully exact, i would kill myself reznov.
24-05-2012, 14:18   #5
reznov
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Quote:
 Originally Posted by cutty9 you need optilase. if you can't get the incircle construction fully exact, i would kill myself reznov.
Wait so if I don't get it right, you will kill yourself? A hefty sacrifice indeed comrade.

Anyone? Any suggestions? Or should I hope for the best as there's no technique?

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 24-05-2012, 16:31 #6 Canard J'ai une araignée au plafond     Join Date: Dec 2008 Posts: 8,114 Mod: Leaving Cert Draw the circle first, draw a triangle around it, add in the construction lines.
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24-05-2012, 16:42   #7
JeaicMaG

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Quote:
 Originally Posted by Patchy~ Draw the circle first, draw a triangle around it, add in the construction lines.
That's... That's brilliant!

 24-05-2012, 16:48 #8 Canard J'ai une araignée au plafond     Join Date: Dec 2008 Posts: 8,114 Mod: Leaving Cert Works every time, FUQ DA SYSTEM
24-05-2012, 18:16   #9
reznov
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Quote:
 Originally Posted by Patchy~ Draw the circle first, draw a triangle around it, add in the construction lines.
If I get the certificate in Maths, I'm dedicating it to YahFaoiSin and you.

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24-05-2012, 18:23   #10
finality
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Quote:
 Originally Posted by Patchy~ Draw the circle first, draw a triangle around it, add in the construction lines.
What if they give you specific measurements for the triangle?

 24-05-2012, 18:30 #11 Togepi Closed Account   Join Date: Oct 2011 Posts: 4,807 They usually just give you the triangle don't they?
 24-05-2012, 19:11 #12 Canard J'ai une araignée au plafond     Join Date: Dec 2008 Posts: 8,114 Mod: Leaving Cert I thought that too. I always thought it was kind of accepted the incircles just dont work, my godly JC maths teacher taught us that sneaky trick. But I guess youd just make the radius around the length of the side or something like that, might take a few tries but if all else fails just do trial and error or do it the conventional way even if it messes up a bit.
24-05-2012, 19:41   #13
ChemHickey
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Quote:
 Originally Posted by Patchy~ I thought that too. I always thought it was kind of accepted the incircles just dont work, my godly JC maths teacher taught us that sneaky trick. But I guess youd just make the radius around the length of the side or something like that, might take a few tries but if all else fails just do trial and error or do it the conventional way even if it messes up a bit.

Use your protractor first. then draw the lines after words

 24-05-2012, 19:51 #14 finality Registered User     Join Date: Feb 2012 Posts: 1,763 I actually don't have trouble with the incircle. Finding the incentre accurately is easy, then just try to sort of line your compass up with the part of the triangle that's closest to the centre, then draw a circle. If it's out by like half a millimetre it's not going to be a problem anyway.
 24-05-2012, 22:51 #15 m4r0s Registered User   Join Date: May 2012 Posts: 1 assume everyone knows it...but you've to draw a 90 degree line to one of the sides from the incentre, works every time for me