Question

Question 7 (ii)

Through a rectangular field of length 90 m and breadth 60 m, two roads are constructed which are parallel to the sides and cut each other at right angles through the center of the fields. If the width of each road is 3 m, find:
The cost of constructing the roads at the rate of ₹ 110 per $m^2$

Answer 1

Here,
PQ = 3 m and PS = 60 m,
EH = 3 m and EF = 90 m
KL = 3 m and KN = 3m

Area of roads = (Area of PQRS) + (Area of EFGH) - (Area of KLMN)
[$\because$ KLMN is taken twice, which is to be substracted]

$=PS\times PQ+EF\times EH-KL\times KN$
$=(60\times 3)+(90\times 3)-(3\times 3)$
$=180+270-9$
$=441m^2$

The cost of constructing 1 $m^2$ road = ₹ 110
The cost of constructing 441 $m^2$ road = ₹ 110 $\times$ 441 = ₹ 48,510
Therefore, the cost of constructing the roads = ₹ 48,510