Question

Which of the following has to be used to measure the length of a curved line?

• A. Only a metre scale.
• B. Only a thread.
• C. A metre scale and a thread.
• D. Only a graph paper.

Answer 1

The correct option is C A metre scale and a thread.

A thread is needed to calculate the length of a curved line. The thread is placed along the curved line. After this, the starting and the ending point of the threads are marked.
The thread is then stretched out in a straight line. This straight thread is placed next to the labelled edge of metre scale to get the length of the curved line.
Hence, both the thread and the metre scale are needed to calculate the length of a curved line.