Question

In dimensioning, the lines enclosing the dimension line are known as ____

(a) Leader line

(b) Dimension line

(c) Extension line

(d) Outline

I have been asked this question during an interview.

The origin of the question is System of Dimensioning topic in section Lines, Lettering and Dimensioning of Engineering Drawing

Answer 1

The correct choice is (c) Extension line

To explain I would say: The extension line encloses the dimension line. It starts and ends with the line to be dimensioned. The extension line is extended beyond the dimension line by 4mm. It helps in defining proper boundaries for the dimension line.