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 = \(4 \times 2400\) 
= \(9600\) \(m\) 
= \(9.6\) \(km\)