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The mystery of  an irregular  pentagon

The mystery of an irregular pentagon

Posers and Puzzles

AThousandYoung
He didn't...Diddy?

tinyurl.com/2p9w6j3b

Joined
23 Aug 04
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26701
Clock
04 Oct 07
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Originally posted by ranjan sinha
Did you google it up to find this out?
😵

rs

H. T. & E. hte

Joined
21 May 04
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3510
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06 Oct 07
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?? was googling of any help?😵😲

s

Joined
25 Jul 04
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3205
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11 Oct 07
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Originally posted by howzzat
No..not at all..Here is my proof which is much much shorter than the one given in ranjan's post dated 29 th Sept. Borrowing the notations and symbols in that post, the area of the pentagon ABCDE is:-
w = Ar. of tr.ABC + Ar. of tr. ADE + Ar. of tr. ACD.
= x + x + (AC/SC)*x. =(2 + c)*x where c = AC/SC..............eqn.(1)
[AC/SC is the rati ...[text shortened]... and (2) we get 2+c = 3+1/c; hence c = {sqrt(5) +1}/2
Thus we get the required value of w/x.
Well done Howzzat. Your solution is far more elegant than the one provided by the poser.

s

Joined
25 Jul 04
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3205
Clock
11 Oct 07
3 edits
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Originally posted by ranjan sinha
Did you google it up to find this out?
Googling is of no help for finding solutions to puzzles. After seeing this pentagon puzzle here, I found it quite challenging and interesting. I posted this puzzle on a site dedicated to "cutting the Gordian Knot" for the wider mathematical community.

s

Joined
25 Jul 04
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3205
Clock
11 Oct 07
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Originally posted by HolyT

Speaking of cheating, someone here is trying to find the answer by posting it in another forum: http://www.cut-the-knot.org/htdocs/dcforum/DCForumID6/648.shtml
No cheating.. See the post above. I posted this puzzle on that site with a view to expose it to a wider interested audience.

h

at the centre

Joined
19 Jun 04
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3257
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13 Oct 07
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Originally posted by sarathian
Well done Howzzat. Your solution is far more elegant than the one provided by the poser.
thx for the compliments ..

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