CBSE Class 9 Maths Coordinate Geometry
Cartesian PlaneTo locate the position of a point in a plane, we require two perpendicular lines, one horizontal and the other vertical.
The horizontal line is called the x- axis and the vertical line is called is called y axis.
The plane is called the Cartesian or the coordinate plane and the lines are called the coordinate axes.
The coordinate axis divide the plane into four parts- each is called a quadrant and denoted by Roman letters I, II, III, IV.
x-coordinate of a point is its perpendicular distance from y-axis and is also called abscissa and y-coordinate of a point is its perpendicular distance from x- axis and is also called ordinate.
If 'a' is abscissa and 'b', the ordinate of a point, then (a,b) are called coordinates of the point P.