Question

The cost of fencing a semi-circular garden of radius 14 m at ₹10 per metre is

(a) ₹1080 (b) ₹1020 (c) ₹700 (d) ₹720

Answer 1

Radius of circle (r) = 14 m
Perimeter of semi-circular garden
$$\begin{gathered} =\pi r+2r \\ =\frac{22}{7}\times 14+2\times 14 \\ =44+28 \\ =72\mathrm{m} \end{gathered}$$
Cost of fencing = 72 $\text{×}$ ₹10 = ₹720
Hence, the correct option is (d).