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alexb
Charter Member
1827 posts
Apr-30-06, 08:41 AM (EST)

"the most elementary theorem of Euclidean Geometry"

 I am at a difficulty understanding D. Pedoe's remark concerning this theorem, see the attached file.What I do not understand is how the theorem about the circumscribed quadrilaterals is relevant here. Refering to the diagram, the theorem would say something likeAC + EF = CF + AE,which would be difinitely equivalent toAB + FD = BF + AD.Not quite was is required by Urquhart's theorem. What am I missing?Thanks,Alex
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mr_homm
Member since May-22-05
May-01-06, 06:11 AM (EST)

1. "RE: the most elementary theorem of Euclidean Geometry"
In response to message #0

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alexb
Charter Member
1827 posts
May-01-06, 10:58 AM (EST)

2. "RE: the most elementary theorem of Euclidean Geometry"
In response to message #1

 Thank you, Stuart.I missed the whole point of directed distances.Alex

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