Question

The radius of a circular park is 2.1 m .find the cost of fencing it at the rate of ₹12 per meter​

Answer 1

Answer:

Question :

The radius of a circular park is 2.1 m .find the cost of fencing it at the rate of ₹12 per meter.

To find :

• The circumference of the circular park.

• the cost for fencing it.

Answer :

$Circumference \: \: of \: the \: circular \: park \: \\ \\ = {\pi \: r \: }^{2} \\ \\ = \frac{22}{7} \times 2.1 = 13.19{m}^{2} \\ \\ \\ \\ Cost \: required \: to \: fence \: per \: meter \: \\ \\ = 12 \\ \\ Cost \: required \: to \: fence \: {13.19m}^{2} \: \\ \\ = 13.85 \times 12 = 158.28$

Therefore ,

Circumference of the circular park = 13.19 cm²

Cost of fencing the circular park = 158.28

Why should we find circumference and not area ?

• Because we are going to fence only the boundary.

• So for finding boundary we should find circumference.

• We know that boundary of a circle is called circumference.