A line may be a combination of points that extends infinitely in both directions. A line is labelled as sort of a line segment with a bidirectional arrow over the label.
The above figure shows a line \(AB\) and is represented as or .
\(100\) metres track is to illustrate the concept of the line. A track may be a line that extends infinitely in both directions without having a fixed starting and ending point.
When three or more points lie on the same line they are called collinear points.
The above figure shows the collinear points \(A\), \(B\) and \(C\). These points are collinear points because all three points lie on the same line.
Arrange the number of cups to validate the concept of the collinear points.
A ray is often defined as a straight line that starts from a point and extends indefinitely in one direction.
The starting point that is fixed at one end is termed as a vertex of a ray. Ray is an additionally one-dimensional entity as we will move endlessly in one direction alone.
The above figure shows a ray \(AB\) and is represented as .
We have a battery-operated torch on one end of the road and light from the torch (called a line segment) is travelling in a straight line towards the other direction. Since we don't know the end of that light, we will say that this line segment from a fixed source may be a ray.