You have an equilateral triangle you want to wrap with a square piece of paper. If the triangle has unit sides, what is the smallest square piece of paper that can be folded around the triangle such that both the front and back sides of the triangle are completely covered by the paper?

(In reply to re: my solution ( oops ) by Michael)

If you don't mind, I took the liberty of copying your drawings and fixing the pre tags around them. 

For future reference, in order to create these drawings you have to either click on the "View Source" box before adding in the "<pre>" OR click on the drag-down menu that says "Formatting >>" and click on "Pre-Formatted".  I know, it's confusing.

          |   s/2   |
+---------|---------+--
|        /|\        |
|       / | \       |
|      /  |  \      |
|     /   |   \1    | s
|    /    |h   \    |
|   /     |     \   |
|  / 60   |      \  |
| /_______|_______\ |
|         |d        |
+---------|---------+--
          |


+---------|
|        /|\
|       / | \    
|      /  |  \
|     /   |   \1
|    /_   |    \
|   /C '._|     \  
|  /      |'._   \
| /_______|___'.__\  
| A       |    B '.\ 
+---------|---------+

             /
           C/
           /'._
          /90  '._
         /        '._     |
        /            '._  |
       /                '.|E                 \
      /                   |'._                \
     /                   y|   '._              \
    / 60                  |    30'._            \
   /______________________|_________'.___________\
  A                       |D   x      B
                          |
                         d|
                          |
-----------------------------------------------------

Posted by Tristan on 2005-10-13 23:26:53