first draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stopfirst draw from the upper left corner to the upper right corner then to the lower right corner from there to the middle next to the lower left corner finally up to the upper left corner then stop

In the lower right corner.

White square is on the lower right corner.

The little square in the lower right corner of a cell is called the fill handle.

Suppose the lower left corner is (0, 0), and the upper right corner is (a, b). Then the upper left corner would be something like (x, b). The lower right corner, because of the symmetry of the parallelogram, would then have to be (a-x, 0).