Question

18. A circular lawn surrounding a circular piece of land is uniformly 7 m wide and its inner
edge is 484 m. Calculate the radius of the inner circle and the area of the lawn.​

Answer 1

Step-by-step explanation:

Radius of inner circle and area of lawn are 77 m and 55902 m^255902m

2

respectively.

Step-by-step explanation:

We are given that A circular lawn surrounding a circular piece of land is uniformly 7 m wide and its inner edge is 484 m

Circumference of circle = 2 \pi r2πr

So, 2 \pi r=4842πr=484

2 \times \frac{22}{7} \times r=4842×

7

22

× r=484

r=484 \times \frac{7}{2 \times 22}r=484×

2×22

7

r=77r=77

Width of lawn = 7 m

Outer radius R = 77+7 = 154 m

Area of lawn = Outer area - inner area =\pi R^2 - \pi r^2 =\frac{22}{7}((154)^2-77^2)=55902 m^2πR

2

−πr

2

=

7

22

((154)

2

−77

2

)=55902m

2

Hence radius of inner circle and area of lawn are 77 m and 55902 m^255902m

2

respectively.

Answer 2

Answer:

hence radius of inner circle and area of lawn r77 metre and 55902 metre square respectively