NCERT Solutions Class 9 Maths Chapter 1 — Orienting Yourself: The Use of Coordinates#

Chapter 1 of Ganita Manjari introduces the Cartesian coordinate system — using ordered pairs $(x, y)$ to describe the exact position of a point in a plane. You will learn to plot points, read coordinates, and use axes, quadrants, midpoints, and the distance idea to orient yourself in two dimensions.

Exercises#

• Exercise Set 1.1 — Reading coordinates from Reiaan’s room, distances of the door from the axes, door widths (1 question)
• Exercise Set 1.2 — Plotting in all four quadrants, table placement, bathroom and dining-room layout (5 questions)
• End-of-Chapter Exercises — Quadrants, collinearity, midpoint formula, distance from origin, circles and squares in the coordinate plane (16 questions)

What you will learn#

• The Cartesian plane: the x-axis, the y-axis, the origin and the four quadrants.
• Plotting points and reading coordinates, and locating objects in rooms and on maps.
• The distance between two points and the midpoint of a segment.
• Checking whether three points lie on a line.

Key formulas and results#

• Distance: $d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$.
• Midpoint: $\left(\dfrac{x_1 + x_2}{2}, \dfrac{y_1 + y_2}{2}\right)$.

Read and revise#

• NCERT Class 9 Maths Chapter 1 (PDF) — the Ganita Manjari Part I chapter itself.
• All Class 9 Maths chapters from Ganita Manjari Part I and Part II.

Frequently asked questions#