Auxiliary projections: a secondary auxiliary view is constructed by projecting from which previously established view?

Introduction / Context:
Auxiliary views are used to display true shapes of inclined or oblique features. Sometimes a single auxiliary view still shows another edge foreshortened; a secondary auxiliary view resolves that by projecting again from the first auxiliary.

Given Data / Assumptions:

• A primary auxiliary view already exists and shows one feature in true size.
• Another direction remains foreshortened in the primary view.
• The goal is to obtain true size in this remaining direction.

Concept / Approach:
A secondary auxiliary is projected from the primary auxiliary, not from the original front/top views. The new projection plane is perpendicular to the direction that is still inclined, producing true lengths and shapes for that orientation.

Step-by-Step Solution:

Verification / Alternative check:
Check that known edges now measure their true design values. If not, confirm perpendicularity of the secondary plane to the still-inclined direction.

Why Other Options Are Wrong:

• Front/Top view: Projecting from the original views does not resolve the remaining inclination.
• None of the above: The correct source is the primary auxiliary.

Common Pitfalls:
Accidentally projecting from the wrong view or forgetting to orient the secondary plane correctly leads to persistent foreshortening.

Final Answer:
Primary auxiliary view