Gabriel's answer to Hhgb gg's Secondary 4 A Maths Singapore question.

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Gabriel
Gabriel's answer
20 answers (Tutor Details)
1st
When they state "solid", you can assume that the entire object is enclosed, unless stated otherwise in a question.

Total Surface Area (SA) in this case is thus as such,

Total SA = Exposed SA for hemisphere + Exposed SA for cylinder
Total SA = 3π(3r)^2 - π(r)^2 + πr(2r) + π(r)^2
Total SA = 29π(r)^2