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Disk Division (Posted on 2004-12-09) Difficulty: 3 of 5
Divide a circular disk into seven parts with a straightedge and compass such that each part has the same area and perimeter.

See The Solution Submitted by Bractals    
Rating: 4.1000 (10 votes)

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re: Solution (picture) | Comment 3 of 17 |
(In reply to Solution by Bob)

http://www.mohawk.mtrsd.k12.ma.us/site/dept/math/jgalvagni/sevenths.bmp

To find the center of a circle, contruct two chords and their perpendicular bisectors.  They intersect at the center.

You only need to divide your extension line into 6 pieces, not 7 (13 if you don't want to find the midpoint afterward)

-Jer

(Nice solution. I was stumped once I remembered you can't construct a regular heptagon.)


  Posted by Jer on 2004-12-09 18:13:58
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