A rectangular lawn whose length is twice of its breadth is extended by having four semi-circular portions on its sides.  What is the total cost in Rs of leveling the entire lawn at the rate of Rs 120 per square meter.  If the smaller side of the rectangular lawn is 12 m ?

102384

Area of lawn = Area of rectangle + 2 (area of larger semicircle) + 2 (area of smaller semicircle)

= 24 × 12 + \(\pi \)(12)² + \(\pi \)(6)²

= 36 (8 + 4\(\pi \) + \(\pi \)) = 36 (8 + 5(3.14))

= 36 × 23.7 m²

cost = 36 × 23.7 × 120 = Rs 102384