RAY
Definition Of Ray
A ray is a part of a line that begins at a particular point (called the endpoint) and extends endlessly in one direction. A ray is also called half-line.
How do we name a Ray?
A ray is named based on the direction in which it extends.
A ray is named with its endpoint in the first place, followed by the direction in which its moving.
In the example shown below, P is the endpoint and Q is the point towards which the ray extends. So, the ray PQ is represented as:
Look at another example. This ray will be called QP as it starts at Q and extends towards P. So, the ray QP is represented as:
Video Examples: Rays
Solved Example on Ray
Ques: Which of the following is a ray?
Solution:
Step 1: The definition of a ray states that "A ray is a part of a line that begins at a particular point (called the endpoint) and extends endlessly in one direction."
Step 2: As per the defition of a ray, among the figures given only Figure 2 represents a ray
Quick Summary
- A ray has one endpoint.
- A ray extends infinitely in one direction.
- Rays are named by their endpoint and a point on the ray (e.g., ray PQ).
🍎 Teacher Insights
Use real-world examples like laser pointers or light beams to illustrate the concept of a ray. Emphasize the importance of order when naming rays.🎓 Prerequisites
- Points
- Lines
- Line Segments
Check Your Knowledge
Q1: Which of the following correctly represents a ray starting at point A and extending through point B?
Q2: Which of the following best describes a ray?
Frequently Asked Questions
Q: Does a ray have a finite length?
A: No, a ray extends infinitely in one direction from its endpoint.
Q: Is ray AB the same as ray BA?
A: No, the order matters. Ray AB starts at point A and extends through point B, while ray BA starts at point B and extends through point A. They are different rays unless A and B are the same point.