Q2 of 36 Page 249

The radius of a circular ground is 63 m. There is 7 m wide road inside the ground as shown in figure 13.10. The blue coloured portion of the road, shown in figure 13.10 is to be repaired. If the rate of repair work of the road costs Rs. 25 per m2, find the total cost of repair.



Given the rate of repair work per m2 = Rs. 25


The radius of the outer circle (R1) = 63 cm


radius of the inner circle (R2) = 63 – 7


= 56 cm


(∵ the distance between the inner circle and outer circle is 7 cm)


Let the measured angle is 60o


area of the repair road = () – ()


= () – (


= 436.15 m2


cost required to repair the road = 436.15 × 25


= Rs. 10,903.9445 (approximately)


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