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CTK Exchange
Eddie
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May-11-06, 04:14 PM (EST) |
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"Angle Trisection"
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OK, I'm sure there must be something wrong with this, since it is impossible to trisect an angle with only compass and straight edge, but what exactly is wrong with this construction? Given angle AOB. Mark off points C and D equal distances from O on A and B respectively. Join C and D. Through point C, draw any line CE not on CD. Mark off point F on CE, any distance from F. Mark off point G on CE, the same distance from F than F is from C. Mark off point H on CE, the same distance from G that F is from C. Join H and D. Using the compass, make an angle CGI equal to angle CHD, leg GI intersecting CD at J. Join O and J. Angle BOJ = 1/3 angle AOB. |
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Eddie
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May-11-06, 06:03 AM (EST) |
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2. "RE: Angle Trisection"
In response to message #1
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Mmmmm...yeh, I see. LOL. Oops. I always hate doing proofs in geometry, because I always think I know for sure something is true, and that doing a long, tedious, complicated, headache-inducing proof of something that I can already tell is true is just not very practical. This is the first time something I "knew" was true has been false. I might think a little better of proofs from now on. Anyway, thanks for showing me my mistake. |
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