Question

The town of Cheraw is constructing a cylindrical water tank to hold the town's water supply. Their initial plans have a 9 ft. Diameter tank and a 25 ft. Tall tank. How much area will they need to paint if they want to paint the outside and top of the tank?

Answer 1

The diameter of the tank = 9 feet

So radius is = $\frac{9}{2}=4.5$ feet

Height of the tank = 25 feet

The top of the tank must be circular with same radius as 4.5 feet

So, to calculate the area of the tank and top, we will add the curved or lateral surface area of tank and area of circle

Curved or lateral Surface area of cylindrical area = 2*PI*r*h

= $2\times3.14\times4.5\times25$ = 706.50 square feet

And area of the circular top = PI*r²

= $3.14\times4.5\times4.5$ = 63.585 square feet

So, total area that will be painted = $706.50+63.585$ = 770.085 square feet

Or rounding up to 2 decimal places = 770.09 square feet.