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Subject: "Avoiding algebra."     Previous Topic | Next Topic
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sfwc
Member since Jun-19-03
Jan-27-06, 05:56 PM (EST)
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"Avoiding algebra."
 
   To see what is going on more easily, the algebra may be eliminated from the second proof at https://www.cut-the-knot.org/Curriculum/Geometry/SquaresAndTrianglesFromJapan.shtml in the following manner:

Let S and T be chosen so that GFST is square, with the same centre as EKHB. So EFK, KGH, HTB, BSE, BCH and EAB are all congruent. Then DS is equal and parallel to TI so that DSIT is a parallelogram.
In particular, A(KDI) = A(KDSTI). Then:

A(KMN) = A(KDI) (Vecten)
= A(KDSTI)
= A(EDK) + A(KESTH) + A(HKI)
= A(EAB) + A(KESTH) + A(HBC) (Vecten)
= A(BSE) + A(KESTH) + A(HTB)
= A(BEKH)
Note that it is not necessary to use G and H anywhere in this proof as S and T may be constructed independently. With a little work, you may be able to make this into a pww.

Thankyou

sfwc
<><


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alexbadmin
Charter Member
1756 posts
Jan-27-06, 05:59 PM (EST)
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1. "RE: Avoiding algebra."
In response to message #0
 
   Very good. Thank you.

> With a little work, you may be
> able to make this into a pww.

Probably, what the Japanese had in mind.


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sfwc
Member since Jun-19-03
Jan-27-06, 06:41 PM (EST)
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2. "RE: Avoiding algebra."
In response to message #0
 
   >Note that it is not necessary to use G and H anywhere in
>this proof
I mean, of course, F and G.

Thankyou

sfwc
<><


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alexbadmin
Charter Member
1756 posts
Jan-27-06, 06:42 PM (EST)
Click to EMail alexb Click to send private message to alexb Click to view user profileClick to add this user to your buddy list  
3. "RE: Avoiding algebra."
In response to message #2
 
   >I mean, of course, F and G.

No doubt.


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