Answer:
 228 cm²
Explanation:
The volume of a cylinder of radius r and height h is given by ...
 V = πr²·h
Filling in the given information, we can solve for r:
 235.5 = π·r²·12
 √(235.5/(12π)) = r ≈ 2.49937 . . . . cm
The area of a cylinder is given by ...
 A = 2πr² + 2πrh = 2πr(r +h)
Filling in the radius and height, we can find the area to be ...
 A = 2π·2.49937·(2.49937 +12) ≈ 227.698 . . . . cm²
About 228 cm² of aluminum are required to make a typical soda can.