*NCERT Solutions of Chapter: Coordinate Geometry. NCERT Solutions along with worksheets and notes for Class 9.*

**Exercise 3.1**

**(1)** **How will you describe the position of a table lamp on your study table to another person?**

**Ans-**

To describe position of the table lamp on my table, we must know its coordinates.

Assume long edges is x -axis and short edges is y-axis.

Now, measure distance from x- axis to lamp is 15cm.

Measure distance from y – axis to lamp is 10 cm.

Therefore, coordinates of the lamp are (15, 10).

**(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. Use 1 cm = 200 m to 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 2 ^{nd} street running in the North – South direction and 5^{th} 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).**

**Ans-**

Street plan is shown below using scale of 200 m = 1 cm.

**(i)** Only one cross street can be referred as (4, 3).

**(ii)** Only one cross street can be referred 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.**

**Ans-**

**(i)** The horizontal line is known as x – axis and vertical line is known as y- axis which are drawn to determine the position of any point in the Cartesian plane.

**(ii)** The parts of the plane formed by these two lines are called as quadrant I, quadrant II, quadrant III and quadrant IV.

**(iii)** These two lines intersect each other at origin.

**(2)** **See fig given below 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.**

**Ans-**

**(i)** The coordinates of point B are (-5, 2).

**(ii)** The coordinates of point C are (5, – 5).

**(iii)** The point identified by the coordinates (-3, -5) is E.

**(iv)**The point identified by the coordinates (2, – 4) is G.

**(v)** The abscissa of the point D is 6.

**(vi) **The ordinate of the point H is – 3.

**(vii)** The coordinates of the point L are (0, 5).

**(viii)** The coordinates of the point M are (-3, 0).

**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.**

**Ans-**

(-2, 4) will lie in quadrant II because x coordinate is negative and y coordinate is positive.

The point is locating on Cartesian plane below-

(3, -1) will lie in quadrant IV because x coordinate is positive and y coordinate is negative.

The point is locating on Cartesian plane below-

(-1, 0) will lie on x – axis because x coordinate is negative and y coordinate is zero.

The point is locating on Cartesian plane below-

(1, 2) will lie in quadrant I because x coordinate is positive and y coordinate is also positive.

The point is locating on Cartesian plane below-

(-3, -5) will lie in quadrant III because x coordinate is negative and y coordinate is also negative.

The point is locating on Cartesian plane below-

**(2)** **Plot the points (x, y) given in the following table on the plane, choosing suitable units of distance on the axes.**

x |
-2 |
-1 |
0 |
1 |
3 |

y |
8 |
7 |
-1.25 |
3 |
-1 |

**Ans-**

Plotting all points on the plane by using scale of 1 cm = 1 unit.

**Helping Points**