Figure 1 (below left) shows a perfect two-point perspective diagram of Farmer Nell’s red-roofed barn and precisely square pigpen in front of it. (“Two-point perspective” means that all lines that are vertical in three dimensions appear perfectly vertical in the diagram, while any two parallel horizontal lines intersect on the horizon line .)
Except something is missing: Farmer Nell’s pigpen is actually divided into nine identical smaller squares, so that if it were viewed directly from above it would appear like the right-hand portion of Figure 2.
Describe a method that will exactly determine the four line segments that must be added to Figure 1 to represent the missing divisions of the pen. Hint: trisecting each of the sides of the pen in the existing diagram and then connecting the two division points on opposite sides won’t work why not?
