In this paper we investigate the size of a bi-dimensional fragmentation
process. A rectangle of dimensions x and y is considered, it is split
into four sub-rectangles with some probability that depends on x and y,
we iterate until the stop of the process. The total number of the all
the obtained rectangles at the end of the process satisfies some
equality in distribution which is resolved , using some tools on
integral equations, via the contraction method.