* Rays extend infinitely: A ray has a starting point but continues indefinitely in one direction. There's no endpoint to define a finite length.
* Measuring length requires two points: To measure length, you need to define a start point and an end point. Since a ray has only a start point, you can't determine a specific length.
What you can do with rays:
* Measure the length of a segment: You can measure the length of a line segment, which is a part of a ray. This segment has a defined start and end point.
* Describe the direction of a ray: You can describe the direction a ray points using angles or other geometric references.
Let me know if you have any other geometry questions!
