Practice30Create account

Fencing a rectangular field cost ₹11,700 at a rate of ₹45 per metre. The field is 80 m long. What is its breadth?

Class 6MensurationMensuration
  • A50 m
  • B100 m
  • C130 m
  • D180 m

Step-by-Step Solution

Length of fencing = 11,700 ÷ 45 = 260 m, and that is the perimeter. Half of it, 260 ÷ 2 = 130 m, is length + breadth, so breadth = 130 − 80 = 50 m. Stopping at 130 m answers "length plus breadth" rather than the breadth; 180 m comes from 260 − 80, subtracting before halving.
Answer: A) 50 m

Key idea: Perimeter shortcuts for special shapes

**Rectangle**: opposite sides are equal, so perimeter = l + b + l + b = 2(l + b).

**Square**: all four sides equal, so perimeter = 4 × s.

**Equilateral triangle**: all three sides equal, perimeter = 3 × s.

**Regular polygon with n sides of length s**: perimeter = n × s.

These shortcuts are just 'add the sides' written shorter.

Master this chapter in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All Mensuration practice questions

More Class 6 Mensuration practice

A wall 9 m long and 4 m high has one window measuring 2 m by 1 m. The wall is to be…Ravi is covering his rectangular floor with square tiles of side 1 m. He has laid the…Shapes A and B are drawn on squared paper (each small square is 1 cm by 1 cm). Both have…Kavya cuts cards of 6 cm by 4 cm from a 32 cm by 20 cm sheet, all placed the same way as…A rectangular lawn is to be fenced all round and also covered with fresh grass, at the…