(Source: http://www.google.co.in/search?hl=en&sugexp=les%3B&gs_rn=5&gs_ri=psyab&pq=footprints
+in+rhythm&cp=16&gs_id=1xs&xhr=t&q=line+perspective&bav=on.2,or.r_qf.&biw=1341&bih=604&um=1
&ie=UTF8&tbm=isch&source=og&sa=N&tab=wi&ei=PHE5UZ2xH4TOrQeblICQAQ#imgrc=tnJYgmIYC4q
GYM%3A%3B_k_83Peg8pcGpM%3Bhttp%253A%252F%252Fcutlerart73.com%252Fimages%252Fper
spective%252Fperspective.jpg%3Bhttp%253A%252F%252Fpiaart.wordpress.com%252Ftwo-point-persp
ective%252F%3B1141%3B674 ; March 8, 2013)

In a two dimensional composition diagonal lines are also used to indicate depth, an illusion of 3D perspective (plate 8A-8B) that pulls the viewer into the picture-creating an illusion of a space that one could move about within. Line is one of the most critical aspects, which help to express and perceive various elements of design. Line creates a path to signify the property of an object by joining two points (plate 5E). Thus, if a feeling of movement or speed is desired, or a feeling of activity, diagonal lines can be used. These elements constitute the functional elements of design. Line can virtually illustrate dimension of larger foreground and receding background perspective (plate 8C).

Functional elements, thus explores various formal elements and principles that are related to functional elements are part of design’s formal structure.  Formal structures are governed by the standard metrics that would eventually provide a standardized form. However, one important issue remains untouched- human emotion.