# PP Dissections

### Author : Gavin Theobald

Having formed a couple of P strips, it is now necessary to overlay the two
strips to form a dissection. The strips must be overlaid at the correct angle.
At this angle the area of overlap of the two strips will equal the area of the
shapes being dissected. The parellelogram defined by the edges of the two
overlapping strips defines the pieces of the dissection. So now, while keeping
the angle constant, the strips are moved around until the
number of pieces is minimised.

Note that the width of each strip must be less than the length of the strip
element of the other strip otherwise the area of overlap will always be too
large whatever the angle between the strips is.

So to dissect a square to a hexagram we first obtain strips for these two
polygons:

These strips are now overlaid:

This gives the following dissection:

Below are some more examples of PP dissections.