The concept of angle emerges in numerous forms as the learning of mathematics and its applications advances through the high school and tertiary curriculum. Many difficulties and misconceptions in the usage of this multifaceted concept might be avoided or at least minimized should the lecturers in different areas of pure and applied mathematics be aware of the way their students have learned the concept in their previous studies. The article presents an analysis of the literature on the mathematical and didactical origins of the concept of angle. The purpose of the analysis is to identify the principal characteristics of the concept required in various contexts of pure-mathematical and applied courses, and to trace the way these appearances might have been previously presented. Attentiveness to students' possible lack of mastery of the notion will hopefully help to prevent or at least minimize difficulties related to it.