NCERT Solutions for Chapter 3 Coordinate Geometry Class 9 Maths
Chapter Name  NCERT Solutions for Chapter 3 Coordinate Geometry 
Class  Class 9 
Topics Covered 

Related Study Materials 

Short Revision for Ch 3 Coordinate Geometry Class 9 Maths
 The location of an object in a plane is found by drawing two perpendicular lines. One of them is horizontal and other one is vertical.
 The plane is called the cartesian plane and the lines are called the coordinate axes.
 The horizontal and vertical lines are called xaxis and yaxis respectively.
 The point of intersection of the xaxis and yaxis is called the origin.
 The coordinate axes divide the cartesian plane into four parts which are called quadrants.
 The four quadrants are known as 1st quadrant, 2nd quadrant, 3rd quadrant and 4th quadrant.
 The distance of a point from yaxis is called its xcoordinate.
 The distance of a point from xaxis is called ycoordinate.
 The xcoordinate is also called abscissa and the ycoordinate is also called ordinate.
 The cartesian plane is also called the coordinate plane or the xyplane.
 If xcoordinate of a point is a and ycoordinate is Î², then (a, Î²) are called the coordinates of the point.
 The coordinates of a point on the xaxis are of the form (Î±, 0) and that of the point on the yaxis are (0, Î²).
 The coordinates of the origin are (0, 0).
 If (x_{1}, y_{1}) = (x_{2}, y_{2}), then x_{1} = x_{2} and y_{1} = y_{2} and if (x_{1}, y_{1}) ≠ (x_{2}, y_{2}), then x_{1 }≠ x_{2} and y_{1} ≠ y_{2}.
 The signs of xcoordinate and ycoordinate of a point in the quadrants are as follows:
Quadrant 
Signs 

x – coordinate 
y – coordinate 

I 
+ 
+ 
II 
− 
+ 
III 
− 
− 
IV 
+ 
− 
Exercise 3.1
1. How will you describe the position of a table lamp on your study table to another person?
Note : Student may suppose different distances from edges.
2. (Street Plan): A city has two main roads which cross each other at the centre of the city. These two roads are along the NorthSouth direction and EastWest direction. All the other streets of the city run parallel to these roads and are 200 m apart. There are 5 streets in each direction. Using 1cm = 200 m, draw a model of the city on your notebook. Represent the roads/streets by single lines.
There are many cross streets in your model. A particular crossstreet is made by two streets, one running in the North – South direction and another in the East – West direction. Each cross street is referred to in the following manner: If the 2nd street running in the North – South direction and 5th in the East – West direction meet at some crossing, then we will call this crossstreet (2, 5). Using this convention, find:
(i) how many cross – streets can be referred to as (4, 3).
(ii) how many cross – streets can be referred to as (3, 4).
Exercise 3.2
1. Write the answer of each of the following questions:
(i) What is the name of horizontal and the vertical lines drawn to determine the position of any point in the Cartesian plane?
(ii) What is the name of each part of the plane formed by these two lines?
(iii) Write the name of the point where these two lines intersect.
2. See Fig.3.14, and write the following:
i. The coordinates of B.
ii. The coordinates of C.
iii. The point identified by the coordinates (–3, –5).
iv. The point identified by the coordinates (2, – 4).
v. The abscissa of the point D.
vi. The ordinate of the point H.
vii. The coordinates of the point L.
viii. The coordinates of the point M.
Exercise 3.3
1. In which quadrant or on which axis do each of the points (– 2, 4), (3, – 1), (– 1, 0), (1, 2) and (– 3, – 5) lie? Verify your answer by locating them on the Cartesian plane.