The Centroid of a Pentomino
The x-coordinate of the centroid of a given
pentomino
(that is placed in
an xy-plane) equals the average of the x-coordinates of the centers
of the 5 squares that form the pentomino. A similar statement holds
for the y-coordinate of the centroid.
See also
Pentomino Puzzles,
Triplicate Pentominoes