V.  Linear Structure - actual and implied lines which can act as a basis for a design. The following types of lines can function to create an overall unified composition: actual lines, the edge between two contrasted areas of value, the axes of shapes or volumes which are significantly longer than they are wide, continuations and eyelines (the projected direction of a figure's gaze within a composition). There are a few basic linear constructions. They are:
 

Grids
 
Rigid Organic Combined organic & rigid
Implied Triangle Diamond
Radial or "X" Circle or Oval Related Curves
Related Diagonals
 
Variations of these basic structures can occur or two or more of these structures could be combined to produce a different structure. Usually, in this case, one of the structures which are used dominates.