What describes non-isometric lines in technical drawing?

In technical drawing, non-isometric lines are those that do not conform to the angles used in isometric projection, which typically shows three dimensions in one view by employing specific angles (usually 30 degrees) for the isometric axes. Non-isometric lines do not align with these standard angles and, therefore, cannot be directly measured for their true lengths on an isometric drawing.

The correct answer highlights that non-isometric lines cannot be measured in true length directly. Instead, to find their length, one must reference their end-points. This is because non-isometric lines can lie at various angles and do not follow the predefined rules of isometric lines, which makes them appear as distorted or skewed in isometric views.

For clarity, non-isometric lines require careful line tracing or measurement between their endpoints to determine their actual lengths, thus emphasizing their difference from isometric lines that maintain direct relationships with the axes and can be measured easily.