All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Shapes > Geometry
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)

Comments: ( Back to comment list | You must be logged in to post comments.)
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
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (9)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information