Question

3 points
18)The radius of a circular
garden is 21 m. How much long
wire will be required to do 4
rounds of fencing to it?
264 m
O 528 m
0 2221 m​

Answer 1

Answer:

528 m is the required wire length.

Step-by-step explanation:

Given :-

Radius of a circular garden = 21 m

To find :-

How much wire will be required to do 4 rounds of fencing to it?

Solution :-

Round = Circumference

Circumference of circle = 2πr

Substituting we get,

2 × 22/7 × 21

44/7 × 21

132 m

∴ For 1 round of fencing, the wire length required is 132 m.

∴ For 4 rounds of fencing, 132 × 4 = 528 m.

Answer 2

Solution:

$528 \: m$

Step-by-step explanation:

Diameter of the circular garden= 21m

$Radius \: = \frac{ \: \: 21 \: }{ \: \: 2 \: \: }$

$Circumference= 2\pi r=2\times\frac{22}{7}\times\frac{21}{2}$

$= 66m$

Length of rope needed for 2 rounds

$=2×66m=132m$

$Cost \: of \: the \: rope= Rs 4\times132=Rs528$

(Or)

Diameter of the circular garden = 21 m

Radius of the circular garden = 21/2 m

Now,

Circumference of circular garden =2 πr

$= 2 \times \frac{22}{7} \times \frac{21}{2}$

$= 22 \times 3 = 66 m$

The gardener makes 2 rounds of fence so the total length of the rope of fencing

$= 2 \times 2 πr = 2 \times 66 = 132 m$

Since the cost of 1 meter rope = Rs 4

Therefore, cost of 132 meter rope = 4 x 132 = Rs 528