If we have three points such as points BCD, we can introduce an important figure in geometry which is called a plane.Think of a plane as a wall or the floor of a room or a flat surface that has no thickness.
To represent the idea of a plane, we can use a four-sided figure such as the one shown in the image provided. It's important to understand that a plane has no edges which means it extends forever in all directions. We can call the figure that is attached in the image provided plane BCD.