What is a ray in geometry?

In geometry, a ray is a line that starts at a specific point and extends infinitely in one direction. It is often represented by a line segment with an arrow indicating the direction in which the ray extends. The starting point of the ray is called the endpoint, and the direction in which it extends is called the direction of the ray.

Rays are used to define angles and geometric shapes, as well as to describe the path of light and other forms of energy. They are often used in geometric constructions, such as in the construction of angles and polygons.

There are two types of rays: half-lines and full-line rays. Half-line rays have only one endpoint and extend infinitely in one direction, while full-line rays have two endpoints and extend infinitely in both directions.

Rays are fundamental elements in geometry and play a crucial role in defining and constructing geometric shapes and figures.