Introduction / Context:
Engineering drawings use several projection systems. Orthographic projection maps 3D geometry onto orthogonal planes (frontal, horizontal, profile) using parallel projectors perpendicular to each plane. This produces true shapes and sizes for faces parallel to the projection plane and is the standard for manufacturing drawings.
Given Data / Assumptions:
- Projectors are parallel to each other and perpendicular to the projection plane.
- First-angle and third-angle conventions determine view placement, not the projection geometry.
- Alternate systems exist (axonometric, oblique, perspective) but serve different purposes.
Concept / Approach:
Orthographic projection’s purpose is to communicate exact geometry without perspective distortion. Because the projection is perpendicular, lengths parallel to the plane are preserved, making it ideal for dimensioning and tolerancing. The description in the prompt matches this method and is the accepted terminology across standards and textbooks.
Step-by-Step Solution:
Define three principal planes: frontal (front), horizontal (top), profile (side).Project features perpendicularly from the object to each plane.Lay out the resulting front, top, and side views using first- or third-angle placement.Dimension features on the most descriptive views to communicate true sizes.
Verification / Alternative check:
Compare to perspective projection: orthographic lacks vanishing points and preserves measurable scale across views.
Why Other Options Are Wrong:
Incorrect: The term “orthographic projection” is the correct name.Known only as perspective projection / Called axonometric projection exclusively: These are different projection systems with different properties and use cases.
Common Pitfalls:
Confusing orthographic with pictorial methods such as isometric (an axonometric variant).Assuming view placement (first vs third angle) changes the projection type—it does not.
Final Answer:
Correct
Discussion & Comments