Question

A rectangular piece of land measures 0.7 km by 0.5 km. Each side is to be fenced with 4 rows of wires. What is the length of the wire needed?

Answer 1

Since the $4$ rows of wires are needed.
Therefore the total length of wires is equal to $4$ times the perimeter of rectangle.
$\text{Perimeter of field} = 2 \times (length + breadth)$
= $2 \times (0.7 + 0.5)$
= $2 \times 1.2 = 2.4 \;km$
= $2.4 \times 1000$ $m$
= $2400$ $m$

Thus, the length of wire = $4 \times 2400$
= $9600$ $m$
= $9.6$ $km$