**Cartesian Plane**: A cartesian plane is defined by **two perpendicular number lines**, A horizontal line(x−axis) and a vertical line (y−axis).

### Quadrants

The cartesian plane is divided into four equal parts, called **quadrants. **These are named in the order as I,II,III and IV starting with the upper right and going around in anticlockwise direction.

### Points in different Quadrants.

Signs of coordinates of points in different quadrants:

**I Quadrant:** ‘+’ x – coordinate and ‘+’ y – coordinate.

**II Quadrant: **‘-’ x – coordinate and ‘+’ y – coordinate.

**III Quadrant: **‘-’ x – coordinate and ‘-’ y – coordinate.

**IV Quadrant: **‘+’ x – coordinate and ‘-’ y – coordinate.

The coordinates of origin O are (0, 0) because it has zero distance from both the axes, so its abscissa and ordinate both are zero.

The coordinates of a point are written by using the following conventions

(i) The x-coordinate of a point is its perpendicular distance from the Y-axis measured along the X-axis (positive along the positive direction of the X-axis and negative along the negative direction of the X-axis). The x-coordinate is also called the abscissa.

(ii) The Y-coordinates of a point is its perpendicular distance from the X-axis measured along the Y-axis (positive along the positive direction of the Y-axis and negative along the negative direction of the Y-axis). The Y-coordinate is also called the ordinate.

(iii) In stating the coordinates of a point in the coordinate plane, the x-coordinate comes first and then the Y-coordinate. We place the coordinates in brackets.

NCERT Solutions class 10 Maths Ch- 3