Basics of Coordinate Geometry

The Coordinate Plane

In the coordinate geometry, all the points are located on the coordinate plane. Take a look at the figure below.

The figure above has two scales – One is the X-axis which is running across the plane and the other one is the y-axis which is at the right angles to the X-axis.

So, in the figure above, the point A has a value 20 on the x-axis and value 15 on the y-axis. These are also the coordinates of the point A. Often these points are also regarded as the “rectangular coordinates”. Please note: The order of the points on the plane is crucial. You have to write the x coordinate ahead of the y coordinate.

Understanding the Concept of Coordinates

• The point of intersection of the x and the y-axis is known as the origin. At this point, both x and y are 0.
• The values on the right-hand side of the x-axis are positive and the values on the left-hand side of the x-axis are negative.
• Similarly, on the y-axis, the values located above the origin are positive and the values located below the origin are negative.
• When you have to locate a point on the plane, it is determined by a set of two numbers. So, first, you have to write about its location on the x-axis followed by its location on the y-axis. Together, the two will determine a single and unique position on the plane.