Which view type is used to dimension features not normal to the orthogonal views of a drawing?

The choice of an auxiliary view is particularly important in technical drawings because it provides a means to accurately represent features that are not aligned with the principal orthogonal views (such as front, top, and side views). When a feature is angled or oblique, viewing it directly in an auxiliary view allows for the true shape and size of that feature to be depicted accurately.

Auxiliary views are created by projecting the object onto a plane that is perpendicular to the feature of interest. This projection eliminates any distortion that could occur when viewing from the standard orthogonal angles, ensuring that dimensions can be applied precisely to the feature. This is crucial in manufacturing and engineering contexts where exact measurements are paramount for creating and assembling components correctly.

In contrast, other view types such as isometric and perspective views convey a more visually realistic representation of an object but do not provide the necessary accuracy for dimensions of features that are not aligned with the primary viewing planes. Section views reveal internal features by slicing through a part but remain limited to illustrating through the main, orthogonal perspectives. Therefore, when it comes to accurately dimensioning features that do not align with these views, the auxiliary view is the optimal choice.