A gardener wants to fence a circular garden of diameter 21 m. Find the length of the rope he needs to purchase, if he makes 2 rounds of fence. Also find the cost of the rope, if it costs 4$ per meter. (Take π as 22/7)

a). total length of rope=132 m

b). total cost of the rope=$528

Step-by-step explanation:

Step 1

To get the total length of rope needed to cover the circular garden twice, we express this as;

P=πD

where;

P=perimeter

π=pi

D=diameter

In our case;

π=22/7

D=21 m

replacing;

P = (22/7) * 21=66 m

2*P=2*66=132 m

total length of rope=132 m

Step 2

The expression to calculate the total cost can be written as;

total cost=cost per meter length*total length of rope

where;

cost per meter=$4

total length of rope=132 m

replacing;

total cost=4*132=$528

total cost of the rope=$528