Question

A square tank has an area of 1600 cm². There are four semicircular plots around it. Find the cost of turfing the plots at Rs 12.50 per m². [Take π = 3.14.]

Answer 1

Let a m be the side of the square.

Area of the square

= a² 

Thus, we have :

a² = 1600 

⇒ a = 40

Area of the plots = 4(Area of the semicircle of radius 20 m)

`=|4(1/2pi"r"^2)"m"^2|`

`=|4(1/2xx3.14xx20xx20)|"m"^2`

= 2512 m²

∴ Cost of turfing plots at 12.50 per m² = Rs (2512 × 12.50)

= Rs 31400