Co-ordinate Geometry is the branch of mathematics in which algebraic methods are used to solve geometrical problems.
Two perpendicular number lines intersecting at point zero are called coordinate axes. The horizontal number line is the x-axis (denoted by X’OX) and the vertical one is the y-axis (denoted by Y’OY). The point of intersection of the x-axis and y-axis is called the origin and is denoted by ‘O’.
A cartesian plane is a plane obtained by putting the coordinate axes perpendicular to each other in the plane. It is also called a coordinate plane or xy plane.