Four square‑tray challenges: each variant uses the 7 identical polyomino pieces; tray sizes vary. Pack all pieces inside the tray—gaps are allowed, overlaps are not.
Each puzzle has a unique solution based on exhaustive computer search; not formally proven..
solutions/– solved layout
Puzzle Design
2025 Yuji Katayose – Puzzle 1
2024 Yuji Katayose – Puzzles 2 - 4
CC0 1.0 (public-domain dedication)
Enjoy puzzling!