Access Answers for SAT Maths Chapter 3 – Coordinate Geometry
Exercise 3.1
1. How will you describe the position of a table lamp on your study table to another person?
Solution:
For describing the position of table lamp on the study table, we take two lines, a perpendicular and a
horizontal line. Considering the table as a plane(x and y axis) and taking perpendicular line as Y axis
and horizontal as X axis respectively. Take one corner of table as origin where both X and Y axes
intersect each other. Now, the length of table is Y axis and breadth is X axis. From The origin, join the
line to the table lamp and mark a point. The distances of the point from both X and Y axes should be
calculated and then should be written in terms of coordinates.
The distance of the point from X- axis and Y- axis is x and y respectively, so the table lamp will be in
(x, y) coordinate.
Here, (x, y) = (15, 25)
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 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, 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).
Solution:
, 1. Only one street can be referred to as (4,3) (as clear from the figure).
2. Only one street can be referred to as (3,4) (as we see from the figure).
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.
Solution:
(i) The name of horizontal 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 quadrants.
(iii) The point where these two lines intersect is called the origin.
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 3.1
1. How will you describe the position of a table lamp on your study table to another person?
Solution:
For describing the position of table lamp on the study table, we take two lines, a perpendicular and a
horizontal line. Considering the table as a plane(x and y axis) and taking perpendicular line as Y axis
and horizontal as X axis respectively. Take one corner of table as origin where both X and Y axes
intersect each other. Now, the length of table is Y axis and breadth is X axis. From The origin, join the
line to the table lamp and mark a point. The distances of the point from both X and Y axes should be
calculated and then should be written in terms of coordinates.
The distance of the point from X- axis and Y- axis is x and y respectively, so the table lamp will be in
(x, y) coordinate.
Here, (x, y) = (15, 25)
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 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, 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).
Solution:
, 1. Only one street can be referred to as (4,3) (as clear from the figure).
2. Only one street can be referred to as (3,4) (as we see from the figure).
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.
Solution:
(i) The name of horizontal 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 quadrants.
(iii) The point where these two lines intersect is called the origin.
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.
