What does arc mean in mathematics?

Mathematically, arc refers to the part between any two points on the circle, which is called arc for short. The arc larger than the semicircle is called optimal arc, and the arc smaller than the semicircle is called inferior arc. A semicircle is neither an upper arc nor a lower arc. Two representations of arc size: arc length and radian. Definition of arc length: the length of an arc passing through two points on a circle is called arc length. The degree of the central angle is equal to the degree of the arc it faces. In mathematics and physics, radian is the unit of measurement of angle. Definition: an arc whose arc length is equal to the radius and whose central angle is 1 radian.