Question

what are the three special marks on a folding rule? 12\ 16\ 18.6\ 19.2\ 24\ 32\

Explanation:

In construction and carpentry (related to the sub - field of Construction Project Management in Social Science), folding rules (measuring tools) often have special marks. 16" is a common mark for stud spacing in construction (as per building standards). 19.2" is also a special mark as it is related to modular spacing in some construction systems. 24" is another frequently used mark for spacing in construction - related measurements.

Answer:

16", 19.2", 24"