Question

The area of a circular field is $11.45$ hectares. Find the cost of fencing it at the rate of Rs. $1.20$ per meter.

• A. Rs. $1450$
• B. Rs. $1433.136$
• C. Rs. $1466.45$
• D. Rs. $1540.33$

Answer 1

The correct option is B Rs. $1433.136$

Area $=11.45\times 10000=114500$ sq. m
We know area of circle $=$ $\pi r^2$
Therefore, $114500\times \frac{7}{22}=r^2$
$\Rightarrow r\approx 190$ m
Circumference $=$ $2\pi r=2\times \frac{22}{7}\times 190=1194.28$ m
Cost of fencing $=1194.28\times 1.20=$ Rs. $1433.136$