From a properly constructed primary auxiliary view, a secondary auxiliary view can be created to reveal true size/length of features still foreshortened. Decide whether this statement is correct.
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ACorrect
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BIncorrect
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COnly possible from principal views
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DOnly for cylindrical parts
Answer
Correct Answer: Correct
Explanation
Introduction / Context: When an edge or plane is oblique (inclined to more than one principal plane), a single auxiliary may not be enough to show true size. A secondary auxiliary resolves the remaining foreshortening by projecting again from the primary auxiliary. We test the correctness of that workflow.
Given Data / Assumptions:
- Primary auxiliary removes foreshortening about one axis.
- Some features remain inclined after the first rotation.
- Secondary auxiliary is built from the primary, not from a principal view.
Concept / Approach: Each auxiliary effectively “rotates” the object relative to a viewing plane. Two successive rotations (primary then secondary) can align an oblique feature parallel to the viewing plane, yielding true size/length necessary for dimensioning and inspection.
Step-by-Step Solution:1) Construct primary auxiliary from a chosen principal view.2) Identify edges/planes still foreshortened.3) Establish a new reference line on the primary auxiliary.4) Project perpendicularly from the primary auxiliary to form the secondary auxiliary where the target feature becomes true.
Verification / Alternative check: Measuring the feature on the secondary auxiliary matches its computed true length or area, confirming correctness.
Why Other Options Are Wrong:“Incorrect”: Conflicts with standard descriptive-geometry methods.“Only from principal views” / “Only for cylindrical parts”: Secondary auxiliaries apply broadly to oblique geometry, not a single shape class.
Common Pitfalls: Placing the second reference line incorrectly; forgetting to keep projectors perpendicular to the new reference line.
Final Answer: Correct