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

Home > Shapes
Seven Region Partition (Posted on 2017-05-27) Difficulty: 3 of 5
The diameter of a polygon is defined as the longest distance between any pair of vertices of the polygon.

Partition a unit equilateral triangle into seven regions so that all seven regions have the same polygon diameter.

How small can that diameter be made?

  Submitted by Brian Smith    
No Rating
Solution: (Hide)
This arrangement has diameter D = (sqrt(3) - 1)/2 ~= 0.366

Draw the three altitudes for each side.
Draw three circles of radius D, one centered at each triangle vertex. Each circle will intersect two sides and one altitude.
For each circle, draw the two segments joining the point on the altitude to the two points on the sides. This forms 3 kites.
Finally, draw the three segments from the three interior points. This forms 3 trapezoids and an equilateral triangle in the center.

Each kite has two sides and both diagonals equal to D. The central triangle has sides equal to D. Each trapezoid has its longer base and both diagonals equal to D.

Jer provides an alternate explanation here.

Comments: ( You must be logged in to post comments.)
  Subject Author Date
SolutionProbably solutionJer2017-05-29 08:31:25
re: Solution?Brian Smith2017-05-28 10:31:08
Some ThoughtsSolution?Steve Herman2017-05-27 21:47:02
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 (11)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information