Postcardproblem 4

Try to place the 12 pentominoes inside the largest possible rectangle, in such a way
that the pentominoes divide the rectangle in 5 parts of equal size.

There may not be more then 5 open areas; also open areas are not allowed to
touch each other in a corner.

The pentominoes must form one shape, so that from any pentomino there is a
pentomino path to any other pentomino.

Find the largest solution in which two of the open areas is a rectangle.

The parts in our example are 36 squares.

Our rectangles are even squares!

We recieve a solution from:

Name |
Country |

Class 2B -KSO Glorieux (42) |
Belgium |

After a little searching we found a solution with three rectangles. Can you do better?