We represent an ordered pair in a Cartesian plane. This plane is formed by two straight lines, *x* and *y, *perpendicular to each other.

The horizontal line is the axis of the abscissa.

(axis *x*).

The vertical line is the axis of the ordinates.

(axis *y*).

The common point of these two lines is called** source**, which corresponds to the ordered pair (0, 0).

## Location of a point

To locate a point on a Cartesian plane, we use the practical sequence:

The 1st number of the ordered pair must be located on the abscissa axis.

The 2nd number of the ordered pair must be located on the ordinate axis.

In the meeting of the perpendiculars to the axes

*x*and*y*, by these points, we determine the point sought. Example:Locate the point (4, 3).