Another form of line within the photograph would be that of 'Diagonals'.
In this exercise I have to illustrate this concept.
The patterned diagonal lines shown on this floor.
The diagonal lines that help make up the pattern in the back of this chair.
The rotten old post shot from this angle are shown to create a diagonal line.
The projected lines along the roof line, window frames (top and bottom) on all levels and the ground all converge to illustrate diagonal lines.