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?

Given:

Length of the land = 0.7 km

Breadth of the land = 0.5 km

Perimeter of rectangular land = 2(length + breadth)

= 2(0.7 + 0.5) km

= 2 × 1.2 km

= 2.4 km

Since each side is to be fenced with 4 rows of wires,

Length of the wire needed = 4 × Perimeter

= 4 × 2.4 km

= 9.6 km

Hence, the length of the wire needed is 9.6 km.