The square water tank has its sides equal to 40 m. There are four semi-circulargrassy plots all round it. Find the cost of surfing the plots atRs.1.25 per sq.m. (Use p = 3.14).

Let ABCD Be the square water park with side 40 m
Â

Area of surfing = 4 (Area of semi-circular grassy plot)

Diameter of each grassy plot = Side of Square water park = 40 m

⇒ Radius of each grassy plot

Also,

Area of semicircle ,

where 'r' is the radius of circle

Putting values in formula, we get

Area of surfing

Cost of surfing for 1 m ² = 1.25 Rs

Cost of surfing for 2512 m ² = 3140 Rs