What are Collinear and Coplanar Points? (GMAT/GRE/CAT/Bank PO/SSC CGL)  Don't Memorise  Summary and Q&A
TL;DR
Points can be classified as colinear, non colinear, coplanar, or non coplanar based on the relationships between lines and planes that pass through them.
Key Insights
 💯 Colinear points have one line passing through them, while non colinear points do not.
 💯 Three non colinear points always form one plane.
 💯 Four or more non colinear points may or may not form a plane, but if they do, they are called coplanar points.
 Coplanar lines are two or more lines that lie on the same plane.
 Non coplanar lines do not lie on the same plane.
 😥 A line and a point will always lie on one plane.
 💯 Colinear points form a line, while non colinear points form a plane.
Transcript
What are Colinear and Coplanar points? How many lines can we draw through one point? We can draw one like this, another one like this and many more! Infinite lines can be drawn through one point. What about two points? How many lines can be drawn passing through both these points? Just one! One and only one line can be drawn passing through two g... Read More
Questions & Answers
Q: What are colinear points?
Colinear points are three points that are positioned in such a way that a single line can be drawn passing through all three of them. They are considered colinear because they lie on the same line.
Q: How many lines can be drawn passing through two given points?
Only one line can be drawn passing through two given points. This is because two points uniquely define a line.
Q: Can three points ever be colinear?
Yes, three points can be colinear if they are positioned in a way that exactly one line passes through each of them. Otherwise, they are considered non colinear points.
Q: What is the difference between colinear and non colinear points?
The difference lies in the existence of a line passing through the points. Colinear points have a single line passing through all of them, while non colinear points do not have such a line.
Q: What does it mean for three points to be coplanar?
Three points are coplanar if exactly one plane passes through all three of them. This means that the three points lie on the same plane.
Q: Do four or more non colinear points always form a plane?
No, four or more non colinear points may or may not form a plane. It depends on their positions. If they do form a plane, they are called coplanar points.
Q: What are coplanar lines?
Coplanar lines are two or more lines that lie on the same plane. This means that the lines share the same flat surface.
Q: Can a line and a point lie on one plane?
Yes, a line and a point will always lie on one plane. It doesn't matter how they are positioned or moved, there will always be exactly one plane passing through them.
Summary & Key Takeaways

Colinear points are three points that lie on the same line, while non colinear points do not have a line passing through all three of them.

Three non colinear points always form one plane, while four or more non colinear points may or may not form a plane.

Coplanar lines are two or more lines that lie on the same plane, while non coplanar lines do not lie on the same plane.

A line and a point will always lie on one plane, regardless of their positions.