The diameter of the tank = 9 feet
So radius is = 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
= = 706.50 square feet
And area of the circular top = PI*r²
= = 63.585 square feet
So, total area that will be painted = = 770.085 square feet
Or rounding up to 2 decimal places = 770.09 square feet.