ANSWER
636,255 cubic centimeters
Step-by-step explanation
Given:
Thickness = 0.02 cm
Diameter = 45m = 4500cm
Recall, Volume of a sphere is:

Determine change in V by differentiating the Volume:

Note: from the given question
dr = 0.02cm
r = 4500/2 = 2250 cm
Recall: for Hemisphere

Substitute the values:

Hence, the amount of paint needed is 636,255 cubic centimeters.