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NCERT
SOLUTIONS
CLASS - 9th
aglase .co
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Book : Mathematics Ncert Solutions | Chapter-3 Maths
Class : 9th
Subject : Maths
Chapter : 3
Chapter Name : COORDINATE GEOMETRY
Exercise 3.1
Q1 How will you describe the position of a table lamp on your study table to another
person?
Consider that the lamp is placed on the table. Choose two adjacent edges, DC and AD.
Then, draw perpendiculars on the edges DC and AD from the position of lamp and
measure the lengths of these perpendiculars. Let the length of these perpendiculars be
30 cm and 20 cm respectively. Now, the position of the lamp from the left edge (AD) is 20
cm and from the lower edge (DC) is 30 cm. This can also be written as (20, 30), where 20
represents the perpendicular distance of the lamp from edge AD and 30 represents the
perpendicular distance of the lamp from edge DC.
Page : 53 , Block Name : Exercise 3.1
Q2 (Street Plan) : A city has two main roads which cross each other at the centre of the
city. These two roads are along the North-South direction and East-West 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 cross-street 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 cross-street (2, 5). Using this convention, �nd:
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Book : Mathematics Ncert Solutions | Chapter-3 Maths
(i) how many cross - streets can be referred to as (4, 3).
(ii) how many cross - streets can be referred to as (3, 4).
Both the cross-streets are marked in the above �gure. It can be observed that there is
only one cross-street which can be referred as (4, 3), and again, only one which can be
referred as (3, 4).
Page : 53 , Block Name : Exercise 3.1
Exercise 3.2
Q1 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.
Answer. (i) The name of horizontal lines and vertical lines drawn to determine the
position of any point in the Cartesian plane is x-axis and y-axis respectively.
(ii) The name of each part of the plane formed by these two lines, x-axis and y-axis,
is quadrant (one-fourth part).
(iii) The name of the point where these two lines intersect is the origin.
Page : 60 , Block Name : Exercise 3.2
Q2 See Fig.3.14, and write the following:
(i) The coordinates of B.
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Book : Mathematics Ncert Solutions | Chapter-3 Maths
(ii) The coordinates of C.
(iii) The point identi�ed by the coordinates (–3, –5).
(iv) The point identi�ed 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.
Answer. (i) The X-coordinate and the y-coordinate Of point are -5 and 2
respectively. Therefore, the coordinates of point B are (-5, 2).
(ii) The x-coordinate and the y-coordinate of point C are 5 and -5 respectively. Therefore,
the coordinates of point C are (5, —5).
(iii) The point whose x-coordinate and y-coordinate respectively is point E.
(iv) The point whose x-coordinate and y-coordinate are 2 and —4 respectively is point G.
(v) The x-coordinate of point D is 6. Therefore, the abscissa of point D is 6.
(vi) The y-coordinate of point H is -3. Therefore, the ordinate of point H is -3.
(vii) The x-coordinate and the y-coordinate of point L are 0 and 5
respectively. Therefore, the coordinates of point L are (0, 5).
(viii) The x-coordinate and the Y-coordinate of point M are -3 and 0
respectively. Therefore, the coordinates Of point M is (-3, 0).
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Book : Mathematics Ncert Solutions | Chapter-3 Maths
Page : 60 , Block Name : Exercise 3.2
Exercise 3.3
Q1 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.
The point (-2.4) lies in the IInd quadrant in the Cartesian plane because for point (-2,4) ,
x-coordinate is negative and y-coordinate is positive. Again, the point (3,-1) lies in the
IVth quadrant in the Cartesian plane because for Point (3,-1) , x-coordinate is positive
and y-coordinate is negative.
The point (-1,0) lies on negative x-axis because for point (-1,0) , the value of y-
coordinate is zero and the value of x-coordinate is negative.
The point (1,2) lies in the First quadrant as for point (1,2) , both x and y are positive.
The point (-3,-5) lies in the Illrd quadrant in the Cartesian plane because for point
(-3,-5), both x and y are negative.
Page : 65 , Block Name : Exercise 3.3
Q2 Plot the points (x, y) given in the following table on the plane, choosing suitable units
of distance on the axes. X.
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Book : Mathematics Ncert Solutions | Chapter-3 Maths
Answer. The given points can be plotted on the Cartesian plane as follows.
Page : 65 , Block Name : Exercise 3.3
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