figures問題

Volume of the cylinder = πr²h = π(9)²(20) = 1620 π cm³

Volume of the sphere = (4/3)πr³ = (4/3)π(9)³ = 972 π cm³

Volume of empty space = 1620 π cm³ - 972 π cm³
= 648 π cm³ = 2035.75 cm³

2014-03-08 00:06:53 補充：
l² = (12)² + r²

(13)² = (12)² + r²

r = 5 cm

curved surface area = (π r l) = (5)(13)π = 65 π cm²

bottom circle area = π r² = π(5)² = 25 π cm²

Total surface area = 65 π cm² + 25 π cm² = 90 π cm² = 282.74 cm²

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