Abstract: The rectangle moves freely according to the random step generated by Monte
Carlo method in the region to be packed in. When the rectangle moves, it is confined in the region
to be packed in automatically, which makes the calculation of feasible region become simple.
After the feasible region is obtained, the rectangle is packed in successfully by the placement
function. Experiments show that above ninety percent of the region to be packed in is filled with
rectangles.

Key words: packing, the rectangle feasible region, Monte Carlo method