What is an isometric projection and how does it differ from an orthographic projection?

• A. Isometric projection is a three-dimensional representation with equal scaling on three axes; orthographic uses multiple two-dimensional views with no perspective.
• B. Isometric projection uses perspective; orthographic uses no perspective.
• C. Isometric projection is a flat 2D drawing; orthographic is 3D.
• D. Isometric projection hides all hidden lines.

Answer: (A)

Isometric projection and orthographic projection describe two ways to turn a 3D object into a 2D image. In an isometric projection, the object is drawn so that the three principal axes are equally foreshortened, giving a single pictorial view where edges along all three directions appear with the same scale and typically meet at 120-degree angles. This creates a 3D-feeling image without any perspective distortion. Orthographic projection, on the other hand, uses parallel projection onto flat planes to produce separate 2D views (such as front, top, and side) with no perspective, so measurements in each view reflect true dimensions on that plane. The combination that describes an isometric drawing as a 3D representation with equal scaling on three axes and orthographic as multiple 2D views with no perspective matches how these methods actually work.