Best orientation for key shapes in oblique projection In oblique projection, how should the most important faces or profiles of an object be oriented relative to the viewing (projection) plane to show them most clearly?

Introduction / Context:
Oblique drawings depict one principal face of the object as true shape and size while projecting depth at an angle. The orientation of the object relative to the viewing plane determines which faces are shown most clearly and without distortion.

Given Data / Assumptions:

• We want the best legibility for critical shapes and dimensions.
• The viewing plane is the plane of the sheet.
• Depth is shown along a receding axis at an angle.

Concept / Approach:
When an important face is parallel to the viewing plane, it appears in true size and shape in an oblique view. That makes features like holes, slot patterns, and contour profiles easy to understand and dimension. If the face is not parallel, it will be distorted or foreshortened, which reduces clarity and can complicate dimensioning rules.

Step-by-Step Solution:

Verification / Alternative check:
Sketch two oblique views of the same bracket, one with the key flange parallel to the viewing plane and one rotated. The parallel orientation clearly shows hole spacing and flange outline; the rotated version distorts these features, confirming the preferred orientation.

Why Other Options Are Wrong:

• Perpendicular: results in extreme foreshortening; not ideal for communicating true shape.
• Adjacent: not a meaningful geometric relation in this context.
• Rotated: can be used for special cases but normally reduces clarity for critical faces.

Common Pitfalls:

• Placing dimensions on foreshortened faces rather than on the true-shape face.
• Using an inappropriate depth angle or scale that visually distorts features.

Final Answer:
Parallel