Many artist work in both two-and three-dimensional forms. But in order to create a sense of depth of three dimensions, on a flat surface canvas or paper the artist must rely on some form of .

geometry and illusion

Explanation: Geometric form are mathematical, precise and include sphere, pyramid, cube,cone and cylinder. illusion is the use of lighting and shadows and rendering of tone and value. Example ; a single light source on a sphere will create a sense of depth of three dimension.

based on the images pictured above, the major difference between the two cathedrals: the cathedral of notre dame and the amiens cathedral, is that the cathedral of notre dame emphasizes the horizontal lines while the amiens cathedral emphasizes the vertical lines.