The angle between two half-lines terminating at the same point is the ratio of the length of the included arc of the circle (with its centre at that point) to the radius of the circle. Symbols:
,
,
... This is a quantity of dimension one with the SI unit
radian
(
), but very often
degrees of arc are used.
Source:
PAC, 1996, 68, 957
(Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996))
on page 961
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
doi:10.1351/goldbook.
