The diagonal of a rectangular field is 18 m, and its area is 126 m2. What will be the total expenditure in fencing the field at the rate of ₹9 per metre?
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Correct answer: A
Explanation
The correct answer is Option 1 i.e. ₹432.
l2 + b2 = 182 = 324 .....(1)
Area = lb = 126 .....(2)
(l + b)2 = l2 + b2 + 2lb = 324 + 252 = 576
⇒ l + b = √576 = 24 m
Perimeter = 2(l + b) = 2 × 24 = 48 m
Fencing cost = 48 × 9 = 432