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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.
Solution
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
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