Question

a closed circular water tank in a subdivision is made up of concreate aluminum. its outer diameter is 8.4 m and its height is 12 m. if it is to be painted on the exterior, then how much total surface area is to be painted?

Answer 1

122.7792 sq. m

Explanation:

diameter= 8.4 m

therefore, radius = r = 4.2 m.......( as radius is 1/2 of diameter)

height = h= 12 m

only the exterior is to painted so the total surface area of the cylinder is taken,

total surface area of cylinder = 2π r( h+r)

=2* 3.14* 4.2*(12+4.2)

=122.7792 sq. m