Hey there :) You'll have to use the formula of cylinder to get your answer : Surface area of cylinder : 2(pi)(r^2) + 2(pi)(r)(h) pi = 22.7 or 22/7 r (radius of cylinder) = 8 mm h = height of cylinder = 20mm
●Hence, just substitute your answer in the given formula and also don't forget to check whether the answer required needs to be in mm or cm.