Definition of angle: In plane geometry, an angle is a geometric object composed of two rays with a common endpoint. These two rays are called the edges of an angle, and their common endpoint is called the vertex of the angle.

So both sides of the angle are rays, and they are two rays with a common endpoint.

Definition of ray: In Euclidean plane geometry, a figure consisting of a point on a straight line and a part next to it is called a ray or a semi-straight line. A ray has only one endpoint, and it extends infinitely from one endpoint to a specific direction.