The vertex.
< the point where the two rays meet is called a vertex.
An angle.
vertex
an angle
angle
an angle
If "this" ray (straight line leaving a certain point) meets end-to-end with "that" ray, then there is a measurable angle between them. (They actually don't HAVE to meet at their ends for this to be true).
The common end point of the sides of an angle is called the vertex. The sides are referred to as rays.
angle
Angle
angle