What is the use of the folding rule and give one care and maintenance of it​

i don't do that but Folding rules can be used for measuring both small spaces and longer distances. They can be transported easily once they are folded up, making them useful when working in the field. Folding rules can also be used to measure a point which is difficult to reach.but it's stu.pid lol

Explanation:

1. they vary with a higher number because boiling is way hotter than melting

it is the most commonly accepted one