Question

what is the definition of angle

Answer 1

In planar geometry, an angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle. Angles formed by two rays lie in a plane, but this plane does not have to be a Euclidean plane.

Answer 2

Angle is a measure of radiation of a given ray about it's initial point.This point is called vertex. Rotation is called angle.