Define collinear points.

Hint: The words ‘col’ means together and ‘linear’ means line. Collinear points are defined for more than two points only. Use these clues to find the definition of the collinear points.

Complete step-by-step answer:
Before we define the collinear points, we need to understand what is a point and what is a line.
A point is an exact position or location in space. It can be represented relative to a coordinate system and origin of the coordinate system. It is a zero-dimensional object, it does not have any length.
A line is a collection of infinitely many points in a straight figure. A line is a one-dimensional object and it has no thickness or breadth. It extends endlessly in both directions. A line segment is a part of a line and has a starting point and an endpoint. A line is represented by a linear equation.
We are now ready to define collinear points.
‘Col’ means together and ‘linear’ means line. Collinear points are three or more points that lie on the same line. Hence, when they are joined and extended they form a straight line.

If the points are not collinear, when they are joined with each other, they form a triangle, which is a three-sided polygon.

Hence, collinear points are points that lie on the same straight line.

Note: Do not confuse collinear points with coplanar points. Coplanar points are points that lie on the same plane and they are different from collinear.