Coordinate Plane with Quadrants notes

Introduction

• A coordinate plane is a flat surface where every point is represented by an ordered pair (x, y).

• It is used in coordinate geometry to locate points and study geometric shapes.

2. Axes of the Coordinate Plane

• X-axis: Horizontal line

• Y-axis: Vertical line

• Origin: Point where X-axis and Y-axis intersect. It is the starting point (0,0).

3. Quadrants

• The coordinate plane is divided into four parts called quadrants:

• Signs of coordinates help identify the quadrant where a point lies.

4. Plotting Points

• To plot a point:

  1. Start at the origin.

  2. Move horizontally according to the x-coordinate.

  3. Move vertically according to the y-coordinate.

  4. Mark the point.

5. Important Points

• Points on the X-axis have y = 0.

• Points on the Y-axis have x = 0.

• The origin does not belong to any quadrant.

• Knowing the quadrant helps in graphing shapes and solving problems in coordinate geometry.

6. Applications of Quadrants

• Locating points on a plane

• Drawing geometric figures like triangles, rectangles, and squares

• Calculating distances and midpoints between points

• Checking alignment of points (collinearity)

Quick Tip to Remember Quadrants

• Quadrants are numbered counterclockwise starting from the top-right:

  • 1 → top-right

  • 2 → top-left

  • 3 → bottom-left

  • 4 → bottom-right