It seems your question is incomplete. Could you please provide more context or specify which endpoint you are referring to? This will help me give you a more accurate answer.
The endpoint.
Is called a radius.
Vertex
Endpoint (Confusingly)
an angle
An angle consists of two rays called sides with a common endpoint called the vertex.
An angle consists of two rays called sides with a common endpoint called the vertex.
vertex
The endpoint.
Endpin.
Is called a radius.
an angle precisely defined as the common endpoint of two rays
An endpoint where two edges intersect on a polyhedron is called a vertex.
Vertex
vertex
Midpoint
an angle