The term `angle' in the international system of units

TL;DR

This paper clarifies the concept of angles in metrology, addressing common misunderstandings caused by ambiguous terminology and mathematical complexities, and emphasizes the importance of precise language for accurate measurement.

Contribution

It provides a clear explanation of angle terminology in the SI system and offers simple rules to prevent misunderstandings about radians.

Findings

Most misunderstandings about radians can be avoided with simple rules

Clarification of angle terminology improves metrological accuracy

Highlights the importance of precise language in measurement

Abstract

The concept of an angle is one that often causes difficulties in metrology. These are partly caused by a confusing mixture of several mathematical terms, partly by real mathematical difficulties and finally by imprecise terminology. The purpose of this publication is to clarify misunderstandings and to explain why strict terminology is important. It will also be shown that most misunderstandings regarding the `radian' can be avoided if some simple rules are obeyed.