The Enclosure Problem
Note the rule used to join them is that they must touch along the full edge of a square and not just at the corners.
It can be seen that an area of 59 (grey) squares is enclosed within the field.
It is also obvious that the pentominoes have not been used very efficiently.
There are two variations on this puzzle -
1. That the outside edge of the enclosure must be a rectangle (having straight edges).
2. That the inside edge of the enclosure must be a rectangle (having straight edges).
The grading table given above does NOT hold for these variations.