==> geometry/pentomino.s <== I've seen several different naming schemes used for pentominoes. This is the system I'm using (I think only F & N require a bit of imagination): FF I L N PP TTT U U V V W W W X X Y ZZ FF I L NN PP T UUU V V W W X YY Z F I L N P T V X X Y ZZ I LL N Y A 3x20 solution (the other solution is easily obtained by a rotation of the section from the Z to the L inclusive): UUXPPPZYYYYWTFNNNVVV UXXXPPZZZYWWTFFFNNLV UUXIIIIIZWWTTTFLLLLV A 4x15 solution: IIIIINNLLLLTVVV UUXNNNFZZWLTTTV UXXXYFFFZWWTPPV UUXYYYYFZZWWPPP 2 5x6 rectangles. Joined side-to-side, end-to-end, or stacked, these enable construction of the 6x10 & 5x12 rectangles, and the 2x5x6 prism: NFVVV YYYYI NFFFV LLYZI NNFXV LZZZI PNXXX LZWTI PPUXU LWWTI PPUUU WWTTT The 2x3x10 and 3x4x5 solutions are tricky to show - I hope these diagrams make sense: A 2x3x10 solution (shown as 2 layers; Y and L are shared between the 2 layers): VVVZIIIIIF UUXTTTWWPP VZZZNNNFFF UXXXTWWPPP VZYYYYNNFL UUXYTWLLLL A 3x4x5 solution (3 layers, V F W & L shared between 2 or more layers): VUUXF VZFFF VNYFW VUXXX TZZZW NNYPW VUUXW TTTZW NYYPP IIIII TLLLL NLYPP -- +------------------- pete@bignode.equinox.gen.nz -------------------+ | The effort to understand the universe is one of the very few things | | that lifts human life above the level of farce, and gives it some | | of the grace of tragedy - Steven Weinberg | +---------------------------------------------------------------------+