A flat surface that extends into infinity in all directions is known as a Plane.

More About Plane

It is also called as two-dimensional surface.
Any three noncollinear points lie on one and only one plane.
A plane has infinite width and length, zero thickness, and zero curvature.

Examples of Plane

The figure shown is a flat surface extended in all the directions. So, it is a plane.

Video Examples: Point Line Plane - Geometry Help

Solved Example on Plane

Ques: Which of the figures represents that one plane is being cut by another?

Choices:

A. Figure 1
B. Figure 3
C. Figure 2
D. None of the above
Correct Answer: A

Solution:

Step 1: A flat surface that extends into infinity in all directions is known as a Plane.
Step 2: Here, only Figure 1 represents that one plane is being cut by another plane.