Class 9 Maths Chapter 1 in the new NCERT book Ganita Manjari (Grade 9, Part I) is Orienting Yourself: The Use of Coordinates. It is the coordinate geometry chapter of the 2026-27 syllabus: you learn to fix any point on a flat surface with two numbers, read the four quadrants of the Cartesian plane, and find the distance between two points with the Baudhāyana–Pythagoras theorem. The full official chapter is below, page by page, with a direct download link from ncert.nic.in.
What Class 9 Maths Chapter 1 Covers
1.1 Introduction opens with the history of grid-based thinking before any formula appears. The streets of the Sindhu-Sarasvatī cities were laid out North–South and East–West about 10 metres apart, so a merchant could find a shop by counting blocks from the centre. The chapter then traces the idea through the Ujjayinī meridian of the early Siddhāntas, Āryabhaṭa’s sines, Brahmagupta’s zero and negative numbers (without which the four-quadrant plane is impossible), Al-Bīrūnī’s astrolabe, Omar Khayyām, and finally Fermat and Descartes, who showed that any point in a plane can be named by two numbers.
1.2 Settling In introduces the story the whole chapter is built on. Reiaan, who cannot see, has moved to a new city, and his sister Shalini maps his room for him on a grid of pins and wool at a scale of 1 cm : 1 foot so that he can feel where the bed, wardrobe and doors are.
1.3 The 2-D Cartesian Coordinate System sets up the x-axis, the y-axis and the origin O (0, 0), with distances to the right of and above O positive and those to the left and below negative. Points on the axes come first (B (4.5, 0), G (0, –4.5), H (0, 4)), then the four quadrants and their sign rules, with S (3, –5) in Quadrant IV and Q (–5, 3) in Quadrant II as worked examples. A Think and Reflect box asks when (x, y) and (y, x) can be the same point.
1.4 Distance Between Two Points in the 2-D Plane uses triangle ADM with A (3, 4), D (7, 1) and M (9, 6): moving 4 units along x and 3 along y gives AD = 5 units, which leads to the distance formula √[(x₂ – x₁)² + (y₂ – y₁)²]. Reflecting the triangle in the y-axis shows that the side lengths stay the same even when the coordinates turn negative.
Exercises in Chapter 1
- Exercise Set 1.1 works on Reiaan’s room plan: how far the door is from each wall, the coordinates of its ends, whether the door is wide enough for a wheelchair, and whether the bathroom door is narrower than the room door.
- Exercise Set 1.2 is drawn on graph paper: placing the study table from three of its feet, checking whether the bathroom door will hit the wardrobe, marking the shower area, washbasin and toilet, and centring a 5 ft × 3 ft table in an 18 ft × 15 ft dining room.
- End-of-Chapter Exercises move to general problems: the quadrants a point can lie in, whether three points are on one straight line without plotting them, midpoints and points of trisection of a segment, points on a circle centred at the origin, finding a triangle’s vertices from the midpoints of its sides, and a city of streets 200 m apart named like (4, 3). Questions 6 to 13 carry an asterisk (*) in the book.
Read Class 9 Maths Chapter 1 Online
More Chapters
- Next: Chapter 2: Introduction to Linear Polynomials
- Hindi medium: Class 9 Maths Chapter 1 PDF in Hindi (स्वयं को प्रवृत्त करना — निर्देशांकों का उपयोग)
- All Maths chapters and the other Class 9 books: Class 9 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
FAQ
Which NCERT maths book is used in Class 9 in 2026-27?
Ganita Manjari, Grade 9 Part I, the new NCERT mathematics textbook. It replaces the older Class 9 Mathematics book, whose first chapter was Number Systems; coordinate geometry now comes first.
What formula does Class 9 Maths Chapter 1 teach?
The distance between two points (x₁, y₁) and (x₂, y₂) is √[(x₂ – x₁)² + (y₂ – y₁)²], derived from the Baudhāyana–Pythagoras theorem in section 1.4. The end-of-chapter questions also lead you to work out the midpoint of a segment yourself.