Ray

A ray is a part of a line that has one endpoint and extends infinitely in one direction. The endpoint of the ray is called the initial point, and the direction in which it extends is called the direction of the ray.

Key Terminology:

1. Endpoint: The starting point of the ray.
2. Infinity: The ray extends indefinitely in one direction.
3. Direction: The way in which the ray extends from its endpoint.

Notation:

A ray can be named by using its initial point and any other point on the ray. The notation for a ray is written with an arrow on top of the two letters representing the initial point and any other point on the ray. For example, if A is the initial point and B is any other point on the ray, then the ray can be denoted as AB or BA.

Examples:

Consider the following examples of rays:

1. Ray AB starts at point A and extends through point B indefinitely in the direction of B.
2. Ray CD starts at point C and extends through point D indefinitely in the direction of D.

Study Guide:

When studying rays, it's important to understand the following concepts:

1. Identifying the initial point and direction of a ray.
2. Notation of a ray using its initial point and any other point on the ray.
3. Practicing drawing and recognizing rays on a coordinate plane.

It's also essential to practice applying the concept of rays in geometry problems to develop a deeper understanding of their properties and applications.

Summary:

A ray is a fundamental concept in geometry, and understanding its properties and notation is crucial for success in math. By grasping the concept of rays and practicing their application, students can strengthen their geometric skills and problem-solving abilities.