AUXILIARY SECTION.— An auxiliary view maybe a sectional, rather than a surface, view. In the upper left part of figure 5-26, there is a single-view projection of a block.
It is desired to show the right side of the block as it would appear if the block were cut away on the plane indicated by the dotted line, the angle of observation to be perpendicular to this plane. The desired view of the right side is shown in the auxiliary section, which is projected from a front view as shown. Because the auxiliary plane of projection is parallel to the cutaway surfaces, these surfaces appear in true dimensions in the auxiliary section.