Definition
Ray
Part of a line with one endpoint that continues forever in one direction.
Continue from this idea into connected AXIO math.
What it means
A ray has one fixed start and one forever direction. In a diagram, a dot marks the endpoint and an arrow shows that the ray keeps going. Ray AB starts at A, passes through B, and continues beyond B.
Remember it
One stop, one forever arrow.
Example
Ray AB starts at A and passes through B. Ray BA starts at B, so ray AB and ray BA are usually different rays.
Watch for
The drawn arrow is finite on the page, but it represents a ray that has no end in its arrow direction.
Common mix-up
A segment has two endpoints, a ray has one endpoint, and a line has no endpoints.
Exact meaning
A geometric ray is the part of a line that begins at one endpoint and extends without end in one direction. It is named with the endpoint first and another point on the ray second.