Parallel Polarized Pentominoes
Here are the 21 pieces packed in a 7x15 rectangle.
The 5x21 rectangle is shown below.
We can look for similar hole models of the pentominoes with a pattern
5-times as wide and a similar hole 2-times as wide. Then we get an area of
5*(25-4)=105 squares. The L,P,T,V.X and Y pentominoes can be scaled this
way but for the other ones we have a problem since the hole can't be placed
without touching the edge.
Perhaps you'd like to construct three replicas of each pentomino. Since
1+2*2+4*4=21 this is possible for most pieces. Only for the X and I-pentomino
the construction failed.
The equivalent set with rectangular forms.