Final answer:
An angle is formed by two rays that originate from the same point and extend in different directions. The intersection of these rays at a common endpoint defines the angle, which can be measured in degrees or radians.
Step-by-step explanation:
A ray, in mathematics, is a straight line that originates at a point and travels infinitely in one direction. When two rays originate from the same endpoint and extend in different directions, the shape formed between them is called an angle. Therefore, the correct definition of an angle, as it relates to the provided options, is: An angle is a figure formed by two rays extending from a common point. This definition aligns with option D, which accurately describes how an angle is formed from the intersection of two rays at a shared endpoint. Angles are fundamental in the study of geometry and are measured in degrees or radians to represent the amount of turn between the two rays.