Pentominos
are the twelve pieces of a well known puzzle. Original this is a flat 2D puzzle. The
twelve pieces are all possible combinations of five squares forming one piece.
Related to the pentominos are the dominos (two squares), triominos (three
squares, two possibilities), tetraominos (four squares, five possibilities as in
the computer game Tetris) and hexominos (six squares, 35 possibilities). The
pentominos are made out of 60 squares in total and can be placed in numerous
forms. Well known is the square of eight by eight units with the little square
hole in the center, as shown on the figure below.

The twelve pieces
are all named to a letter of the alphabet to which they most look like. Some
pieces are very similar to a letter as the X- or V-piece. But to see a letter in
the F- or N-piece requires more fantasy.

A nice variation of
this puzzle is to use cubes in staid of flat pieces. You get twelve pieces which
can form for instance a block of 3 x 4 x 5 units. This puzzle is shown in the
picture below. It is not difficult to make this puzzle by yourself. Saw 60 cubes
out of a square stick and glue the cubes together according to the diagram
above. You can also saw the twelve pieces out of a plate of pinewood.
Paint the pieces in different colors for a nice effect.

You can make
different puzzles with the twelve pieces. For example the block above of 3x5x4
units (which has
3940 possible solutions). If you have solved this puzzle try to make the figures
below.

A second task is to
build larger pentomino pieces. The pieces will become two times as big as the
original and three units high. The examples below show how you can make a F, L
or Y piece. Be careful if you want to rebuild all pieces: Two pentomino pieces
cannot be made.

Several solutions
of these puzzles can be found on this site, but the puzzles have often more than
one solution. Try also to invent tasks by yourself.