Find the cost of planting grass in a circular lawn of radius 21m at the rate of Rs 15 per - Maths - Perimeter and Area

Question

Find the cost of planting grass in a circular lawn of radius 21m at
the rate of Rs 15 per sq m Also find the cost of fencing the lawn
at the rate of Rs 5 per m

Manbar Singh · Accepted Answer

We have,radius of the circular lawn = r = 21 mNow, area of the lawn
= π r2 = 227 × 21 × 21 = 1386 m2cost of planting
grass in 1 m2 area = Rs 15cost of planting grass in 1386 m2 area =
Rs 15×1386 = Rs 20790Now, circumference of lawn = 2πr =
2×227×21 = 132 mcost of fencing 1m of lawn = Rs 5cost
of fencing 132 m of lawn = Rs5×132 = Rs 660

Find the cost of planting grass in a circular lawn of radius 21m at the rate of Rs.15 per sq. m. Also find the cost of fencing the lawn at the rate of Rs. 5 per m.