How will you describe the position of a table lamp on your study table to another person?
Consider the lamp as a point and table as a plane. Choose any two perpendicular edges of the table. Measure the distance of the lamp from the longer edge, suppose it is 25 cm. Again, measure the distance of the lamp from the shorter edge, and suppose it is 30 cm. You can write the position of the lamp as (30, 25) or (25, 30), depending on the order you fix.
(Street Plan): A city has two main roads which cross each other at the centre—one running North–South and the other East–West. All other streets run parallel to these and are 200 m apart, with 5 streets in each direction. Using the convention that the cross-street formed by the 2nd North–South street and 5th East–West street is written as (2, 5), 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)
The Street plan is shown in the figure given below.
Both the cross-streets are marked in the figure above. They are uniquely found because of the two reference lines we have used for locating them.