Create an architectural four-square-grid plan.

Input parameters:

1. Bn → Boundary rectangle within which the 4-square grid will be laid out.
2. R1 → Relative weighting of the first row.
3. R2 → Relative weighting of the second row.
4. C1 → Relative weighting of the first column.
5. C2 → Relative weighting of the second column.

Output parameters:

1. S00 → The cell in the bottom left of the grid.
2. S01 → The cell in the bottom right of the grid.
3. S10 → The cell in the top left of the grid.
4. S11 → The cell in the top right of the grid.