In an isometric drawing, any straight line not parallel to one of the three principal isometric axes (120° apart) is termed what? Identify the correct name for lines that do not align with the isometric axes.

Introduction / Context:
Isometric drawings represent three-dimensional objects with the principal axes equally separated by 120°. Edges that coincide with these axes are easy to measure and draw using isometric scaling. However, many features lie at other orientations. Recognizing how these off-axis lines are classified is a core drafting skill.

Given Data / Assumptions:

• The drawing is an isometric representation (equal foreshortening along the three axes).
• The line of interest is not parallel to any isometric axis.
• Terminology options include nonisometric, trimetric, multiview, and dimetric terms.

Concept / Approach:

Lines parallel to the isometric axes are called isometric lines. Any line that is not parallel to those axes is called a nonisometric line. Such lines cannot be measured directly using the isometric scale along the axes; instead, their endpoints are located and then connected, or auxiliary construction techniques are used to approximate curves and angles.

Step-by-Step Solution:

Verification / Alternative check:

Drafting texts clearly distinguish isometric vs. nonisometric lines for measurement and construction. Nonisometric lines often require locating key points from orthographic views, then connecting those points in the pictorial.

Why Other Options Are Wrong:

Trimetric and dimetric are types of axonometric projections (not line names) with unequal or partially equal foreshortening, respectively.

Multiview lines is not a standard term for isometric classification; multiview refers to orthographic projections (front/top/side).

Common Pitfalls:

Trying to measure nonisometric lines directly using axis-aligned scales, which causes length or angle errors. Always use endpoint transfer methods.

Final Answer:

Nonisometric lines