How can you create an illusion of spatial depth in a two-dimensional design?
a. by adding horizontal and vertical lines
b. by using overlapping shapes and forms
c. by using complementary colors
d. by varying the weights of outlines

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.