Journal of the Mathematics Council of the Alberta Teachers’ Association
Volume 34 Issue 1, May 1997
29 – 33
Jane Barnard
An angle is the union of two rays sharing only a common endpoint. Angles are frequently measured using degrees. The ancient Babylonians used a sexagesimal, or base 60, numeral system and assigned measure of 360 degrees to one revolution of the circle. They divided a circular region into 6 sectors and subdivided each sector into 60 more sectors, giving 360 subdivisions. Each small subdivision is called a degree.