Congruent shapes = the “20 problem”

Make three congruent figures with the pentominoes by dividing the set in three sets of 4 pieces

Seven examples are shown below:

Solution 6 is the only one we have found where the hole has the shape of a pentomino.

Solution 7 has a vertical axis of symetrie.

 We received solutions from::
Julie Deriemaker – Belgium
Jin Honda - Japan
Roel Huisman – The Netherlands
Helmut Postl - Austria
Pieter Torbijn – The Netherlands
Aad van de Wetering – the Netherlands