Haryana State Board HBSE 9th Class Maths Solutions Chapter 3 Coordinate Geometry Ex 3.1 Textbook Exercise Questions and Answers.

## Haryana Board 9th Class Maths Solutions Chapter 3 Coordinate Geometry Exercise 3.1

Question 1.

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

Solution :

Consider, the lamp as a point and table as a plane. Choose any two perpendicular edges of the table, say OX and OY. Measure the distance of the lamp from longer edge i.e., distance of P from longer edge OX. Suppose it is 30 cm. Again measure the distance of the lamp from the shorter edge i.e., distance of P from the shorter Edge edge OY. Suppose it is 25 cm. You can write the position of the lamp as (25, 30) or (30, 25), depending on the order you fix.

Question 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 1 cm = 200 m, draw a model of the city on your note-book. Represent the road/ 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:

The street plan is shown in the figure given below:

(i) There is only one cross street, which can be referred to as (4, 3).

(ii) There is only one cross street, which can be referred to as (3, 4).