Question

The area of a circular lawn is 616 m2. Find its circumference. Find the cost of
fencing it at the rate of 50 per m.​

Answer 1

GiveN :

• Area of Circular Lawn = 616 m²

To FinD :

• Circumference and price of fencing lawn at rate of Rs. 50 per m.

SolutioN :

Use formula for Area of Circle :

⇒Area = πr²

⇒616 = 22/7 * r²

⇒r² = (616*7)/22

⇒r² = 4312/22

⇒r² = 196

⇒r = √196

⇒r = 14

∴ Radius of Circular Lawn is 14 m.

_____________________

Now, use formula for Circumference of circle :

⇒Circumference = 2πr

⇒Circumference = (2 * 22 * 14)/7

⇒Circumference = (44 * 14)/7

⇒Circumference = 616/7

⇒Circumference = 88

∴ Circumference of Circlular lawn is 88 m.

____________________

Cost of fencing it,

⇒Cost = 88 * 50

⇒Cost = 4400

$\therefore$ Cost of fencing lawn is Rs.4400.