It's the vertex
The vertex.
Two rays that share a common endpoint share an angle. See the related link, "Rays forming an angle" for a picture.
an angle is composed of two rays that have the same endpoint.
Two rays that share an endpoint form an angle.
An angle is the union of two rays with a common endpoint.
Angle An angle is formed by 2 rays extending from the same endpoint.
The common endpoint of 2 rays that form an angle is the vertex.
an angle has two rays with the same endpoint.
Two rays that have the same endpoint form an angle.
vertex
An angle is formed by two rays with a common endpoint.
An angle is formed by two rays with the same endpoint. If the two rays are perpendicular to one another, they form a right angle.