The dome of a building is in the form of a hemisphere. Its radius is 63dm. Find the cost of painting it at the rate of Rs. 2 per sq.m.

Explanation

Radius of hemisphere `= 63 dm`
`1 dm = 0.1 m`
So, `63 dm = 6.3 m`
So, radius of hemisphere `= 6.3 m`
Curved surface area of hemisphere `= 2 pi r^2= 2 xx 3.14 xx (6.3)^2`
`= 249.2532`
Cost of painting `1 sq.m. = Rs.2`
Cost of painting `249.2532 sq.m.= 249.2532 xx 2=498.5064`
Hence the total cost of painting is `Rs. 498.5064`