Question

The area of a circular playground is 22176 m². Find the cost of fencing this ground at the rate of Rs 50 per metre.

Answer 1

According to the question,

Area of the circular playground = 22176 m²  ...(Given)

Let r be the radius of the circle.

∴ πr² = 22176

⇒ `22/7 "r"^2` = 22176

⇒ r² = `22176 xx 22/7`

⇒ r² = 7056

⇒ r = 84

∴ Radius of the circular playground = 84 m

Now, circumference of the circle = 2πr

= `2 xx 22/7 xx 84`

= 528 m

Cost of fencing 1 meter of ground = Rs 50

∴ Cost of fencing the total ground = Rs 528 × 50 = Rs 26,400