use 5 y-pentominoes to make a symmetric figure:

    5        5   
  55554    55554 
  1   4    1   4 
 11   44  11   44
  12 34    12 34 
  12 33    12233 
   223      2 3  
   2 3      2 3  

Thanks, 

 Trygve Flathen
---------------------------------------
Dear Ed,
 
     Here's one such shape.
 
AAAAB
C A B
CC BB
CD EB
CDDEE
 D E
 D E
 
     Sincerely,
 
     Bryce Herdt
---------------------------------------
         +--+
         |  |
   +--+--+  +--+--+
   |           |  |
   +--+--+--+--+  +
   |  |########|  |
+--+  +--+##+--+  +--+
|     |  |##|  |     |
+--+  +  +##+  +  +--+
   |  |  |##|  |  |
   +  +  +--+  +--+
   |  |     |     |
   +--+  +--+  +--+
      |  |  |  |
      +--+  +--+

Obviously, the top crossbar could be flipped downwards, but I like
the fact that this arrangement uses the same handedness for all pieces.
Nice puzzle - don't know why it took me so long to find the answer.

-- Roger Phillips 

---------------------------------------

Ed:

Interesting challenge!

 1 2
 1 2
11223
41 23
44 33
4 5 3
45555

Has anyone done the other nonsymmetric pentominoes or the L-tetromino?

Bob Wainwright

---------------------------------------

Here it is:

 1 2 
 1 2 
11223
41 23
44 33
4 5 3
45555

Alex Fink