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

Home > Just Math
mini equilateral over mega equilateral (Posted on 2021-01-28) Difficulty: 3 of 5
Let n be a natural number. Determine the minimal number of equilateral triangles of side 1 to cover the surface of an equilateral triangle of n + 1/2n

No Solution Yet Submitted by Danish Ahmed Khan    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Answer | Comment 1 of 2
A simple lower bound is given by the ceiling of the squared area of the larger triangle.

(n+1/(2n))^2 = n^2 + 1 + 1/(4n^2)

The last term is positive and smaller than 1, so the ceiling is n^2+2.

This gives a lot of room to spare and it achievable for any n.  Basically you can start at a corner and tile the first (n-1)^2.  Then put one in each of the other corners.  The remaining equiangular hexagon can be covered by the 2n-1 triangles with minimal overlap.

It's slightly different for even/odd n.  I'll make a picture if I get a chance. 

  Posted by Jer on 2021-01-28 08:30:10
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 (17)
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