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Article #172Re: Cyclic Quadrilateral Problem
From: Scott Phung
Date: Tue, 01 Apr 1997 00:00
Date: Tue, 01 Apr 1997 00:00
54 lines
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2560 bytes
Brian McCague <brian@mccague.demon.co.uk> wrote: BM> In article <5hnv2g$95s@opus.vcn.bc.ca>, Scott Phung <landmark@vcn.bc.ca> BM> writes BM> >Here's a math problem that's been on my mind: BM> > BM> > Suppose I have a circle with a radius r. Then into it is BM> >inscribed a cyclic quadrilateral. Is the area of this cyclic BM> >quadrilateral = 2r^2? I know that if the cyclic quadrilateral BM> >was a square, then the area of the square = 2r^2. BM> > BM> > More Generally, if a polygon is inscribed into a circle with BM> >a radius r, would the area of the polygon inscribed = area of BM> >regular polygon inscribed? BM> > BM> > Also, does the center of the circle lie on any of the two BM> >diagonals of the cyclic quadrilateral? BM> > BM> > Can anyone confirm the any of above? BM> > BM> > BM> Consider a quadrilateral formed by four points that are very close BM> together on the circle's circumference. It follows that the answer to BM> the above questions is 'no'. BM> -- BM> Brian McCague But does the angles diagonally opposite of each other add to 180? A ......... D . . B ..... C Does <B + <D = 180 and <A + <C = 180? Yes, it's easy to image four points close together, but do these four points satisfy the above? Perhaps you can provide an example. If it adds to 180, my mistake and I will be beleive that this area is smaller than that of a inscribed square. Thanks, Scott Phung. -- /***********************************************************************/ /* Tagline: */ /* It is easier to resist at the beginning - Leonardo da Vinci */ /* */ /* Email: landmark@vcn.bc.ca */ /***********************************************************************/
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 1130d6,2685f1246c1c8405 X-Google-Attributes: gid1130d6,public X-Google-Thread: 1077c2,2685f1246c1c8405 X-Google-Attributes: gid1077c2,public X-Google-Thread: f7972,2685f1246c1c8405 X-Google-Attributes: gidf7972,public From: landmark@vcn.bc.ca (Scott Phung) Subject: Re: Cyclic Quadrilateral Problem Date: 1997/04/01 Message-ID: <5hs7fa$4p7@opus.vcn.bc.ca> X-Deja-AN: 229984706 References: <5hnv2g$95s@opus.vcn.bc.ca> <aJnC8LAIl6PzEwOa@mccague.demon.co.uk> Organization: Vancouver Community Net Newsgroups: can.schoolnet.math.sr,alt.math.recreational,alt.uu.math.misc